When I started the yellow pages was where it was at the adult entertainment advertisements. Every hotel had a phone book. The bars, casinos, & nightclubs are always an option for those who can freelance. I believe a true professional woman of leisure has the ability to hook anyone at anytime & anyplace. For example: the gym, the grocery store, traveling, so many options. I am curious as to what you would, do if you did not rely on TER, P411, etc.? Sharing is caring. Thanks I’m advance. Smile for me! Xoxo

Beyond the Yellow Pages, which I did use while away, there were the weekly entertainment papers in most large cities.  

Ditto.

In Boston, it was the weekly Boston Phoenix newspaper. Hundreds of escort, massage, phone sex ads. I used it all the time. I saw my first escort, Penny, in August 1986. I saw her for about 20 years. We still meet up for just dinner around Xmas each year.  

Do you mean a conventional date or a "date"? LOL

Now to answer your question....

It was a hotel/casino that was a true "bawdy house" and only closed about five years ago. A huge horde of Chicas would do "the walk of shame" through the lobby and the casino. What a show. You picked one out and took her right up to your room. I thought I'd died and gone to, er, Heaven. Remember the "Titty Twister" in Tarantino's "From Dusk 'Til Dawn?" That was the old Del. Minus the vampires.
The good news is they've all shifted down to Jaco (about 90 minutes away) to the Cocal Resort and Casino. It's a pussy buffet.

Because even if I should try and have a few girlfriends, that comes  with  a lot of drama and maybe  even I  get stuck with unwanted kids .
Maybe I would practice polygamy,based on agreement and benefits, without marriage, so as not break the law.  
There are always girls around who are not looking for anything  serious, and many are materialistic  .Maybe I would becone a sugar daddy- with benefits. 😁
A few topless clubs and massage parlors are places where  extra services can be found..

Usenet (usenet newsgroups) goes back to 1979.  VERY useful and helpful ... and anonymous. There were such groups as:
rec.arts.movies.erotica (RAME)
alt.sex.strip-clubs (ASSC)
alt.sex.prostitution (ASP)
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I was able to pick up helpful info from usenet long before TER.  
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But usenet is post-internet, not what the OP, QB, was asking about.  
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I think QB was asking a history question: What did people actually do before the internet? But it could have been a more theoretical question: What WOULD people do if there was no internet? Cable TV was coming along faster than the internet, e.g., The Robin Bird Show. I think that demand might have led to more advertising on cable, followed by rounds of regulation and deregulation.  
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Put another way, "What would you INVENT to promote this sort of dating if the internet had not come along?"

this is where the Korgs would have an easier transition.
They already have a pretty decent client list, an old-time black book, and would just adjust the way they operate to stay in business.

Many guys had at least one or more pimps in their Roll-A-Dex or on speed-dial on their land-line phone.  There were the ads in the weekly rags for girls offering everything from massages to just about anything else.  There was also the Corral Club at Texas Stadium (and still is at Jerry's world) during Cowboy's games, the bars at most high-end hotels had a plethora of working girls that were easy to spot, and the low end were walking along Harry Hines Blvd. in Dallas.  
This game has been played for as long as there has been women and the men who wanted them, and it will always be around no matter if we have the internet, yellow pages, or whatever.  The girls will keep on selling and the boys (and some girls) will keep on buying.  The sex biz is the longest consectively running business model in the world and will remain that way until the last day of planet earth.
The internet has made it much easier for girls to operate as independents, without the nastiness of a pimp or the costs of an agency.  It has also made it operationally easy to set up and attract customers without having to post up somewhere like a hotel bar or street corner.  As a result, the quantity and quality of providers has improved exponentially (per my experience).  Sure, there were quality providers before the internet, but now, with the ease of setting oneself up, the business model for working girls is much more attractive than it used to be.
The internet has also made it much easier and safer for all involved, provided that one keeps their wits about themselves and trusts their inner voice.  Johns can now easily do research on sites like TER and others.  Providers can easily screen clients, as well.  In the days before the internet, is was like the wild, wild west.  There were dangers around every corner of the hobby, for clients and providers, and no real way to go into a date with any reasonable level of comfort that it was going to end well.    
I didn't start my response with a plan to write such a long response.  I'm sorry for rambling.  However, it did give me an opportunity to think about it more than I usually do.  In closing, the bottom line for me is that without the internet, I don't think that I would be a hobbyist today.  
Smile for me!  EOM

In the 1970's there was Al Goldstein's Screw Magazine and even the advertisements in the Village Voice not to mention the Oak Bar at the Plaza Hotel. Even further back, take a look at book entitled City of Eros on the many brothels in 19th century NYC and the gentlemen's guides to those establishments.

http://www.theeroticreview.com/discussion-boards/ter-general-board-12/history-of-review-sites-too-924666
"I'm sure there was ancient graffiti ("For a good time, see Clytemnestra, VI VI IX II IV VI VIII."), but the oldest commonly known review would probably be that of Mary Magdalene in The Epistles. ..."
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and references to other posts, therein.
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Old pamphlets: http://www.theeroticreview.com/discussion-boards/ter-general-board-12/pamphlet-from-100-years-ago-448849
"Pamphlet currency: 6 months - 1 year?
Tabloid currency: one week?
Internet currency: HOURLY!"
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Operative phrase is "as we know it."

I like that.. Got my dick hard...  

I thought Al Gore invented the internet?  Or was that the web, or both..

Not only at the Del Rey but at the Cocal. After all, since most of their clients are gringos they couldn't do much business without speaking English.
I just spoke to a buddy who was in San Jose last week. He said the Del was open again but nothing like its former self. The casino is gone and there are only a few girls there. He said most of the action is at a place called Taormina. The Sportsmen's Lodge is still around, too, I believe.

You went to the local pickup bar and tried to your best to get lucky for the evening.  There were advantages
1.  You got to not only see, but also talk to your potential partner for the evening
2.  There was no “charge by the hour bullshit”
3.  It usually only cost you a few drinks.
4.  There was never a no show or getting ghosted when you showed up.  You knew before you walked out the door.

OMG i remember in the 80s and 90s the yellow pages would have up to 50,  FIFTY! pages for escort agencies,  many had full page ads .   of course they all presented as if they were all proper women to be on your arm for that business dinner.   and to be fair many were just that.  

These ads in "alternate newspapers" were invariably on the last page, therefore the term (and website) Backpage.

Then now it's a "baldy" house.   Lol

You always had a few phone numbers hidden on slip of paper deep in your wallet. Some of these numbers where published in the small papers others have mentioned. The best ones were not. When a opportunity to see a provider came up you would call your best # and ask what they had available . I had some great times and met many outstanding providers this way.  

This was Las Vegas in the 80s.  It was so easy.  I’d find an ad in the yellow pages; back then Las Vegas had at least 80 pages of adds.  Then I would call the number in the add and they’d ask me what kind of lady I’d like to see.  My standard reply was a busty brunette.  They’d tell me to stay by the phone and wait for a call in about five minutes from (insert name here).  The escort would usually call me in about 5-10 minutes and we’d settle on a time at my hotel, which was usually only about a half hour later.  Escort would then show up and she’d ask me what services I’d like and how many pops I wanted.  My standard reply was three BBBJ/CIM for the hour (I was in my early 20s).  If the escort didn’t want to go for three pops she’d politely decline, call the agency and they would find a gal who could accommodate me.

In the day newspapers ran classified ads for massage parlors.

1) Street action
2) "Massage" Parlors
3) Walking through a hotel bar and a way-out-of-your league woman makes eye contact with you.
4) Red-light districts
5) Taxi drivers
6) Hang out with middle aged businessmen going through a midlife crisis
7) Be young, fit, good-looking and able to hold a conversation

Ah, those glorious days in Chicago's Rush St, SF's Marina, NYC's SoHo, LA's Sunset strip.
Youth is wasted on the young..

singles bars, where you either perfected your social game and learned how to seduce a woman without paying her, or you spent a lot of time whacking off alone.  Those of us that came of age in this environment have a distinct advantage with women in general over those who came along in later generations and spent wasted time texting to try to get dates rather than looking them in the eye across cocktails and pretending to be sincere.  Those were the golden days of my youth, too.  

I remember phone booths in the UK plastered with postcards for call girls.