Often the HE is a part of the basic fee, though a little tip is often appreciated.  (Maybe I should re-phrase that.)

Offer a small gratuity at the end if the service was good.

That said, some gals do have a two or even three tier fee schedule for massage with HE and then GFE or FS.  Some also offer fetishes and/or BDSM or even PSE for even more.  They are more uncommon, however

I suspect most important things to you at this early stage are appearance (you find her visually attractive) and maybe a bunch of personality points based on her website, posts to TER boards or what her reviews say about her. If you are ignoring services for the time being, that's perfectly OK. However, you COULD narrow your search based on other criteria and look only for attractive, personable women who do not offer FS at all.

That being said, anything you pay to a hostess is for her time and companionship only , regardless of whether you choose bask in her beautiful presence, to play a game of chess (bring your own set and board in case she doesn't have one), bake a cake or engage in other activities. In your early goings, you'll just have to pay her rate before you can discuss unlisted options.  

USUALLY, an escort has no problem doing only what you ask and not forcing you to do anything you don't want to do, but there a few out there who really want to share and enjoy a FS experience and might push you to experience more than your original intentions - not necessarily a bad thing, I might add.

Bottom line: If you want to meet those beautiful women, be prepared to pay their listed fees regardless of any of your self-imposed limits.

... that you're looking for an experience beyond what you can get at a massage parlor. Perhaps a "GFE" type of experience, but without FS. If that's what you seek, there are many providers who offer a GFE experience without FS. As has been said, many if not most FS providers are glad to trim their menus--but don't expect them to trim their rates unless they offer non-FS rates also.  

But you might be better off with providers who specialize in massage + HE.  You didn't say where you live, but there's excellent providers in that category.  You can use the TER search features to zero in on massage-type providers.

but it's your time & many would agree.  There are lots of FBSM gals out there as well, with lesser rates but they don't get reviewed as often.  There are all levels of massage...  she says clothed, topless, nude, body to body, etc.  It's a good way to break into the hobby & just get used to the game.  It's how I started & I still do sometimes.