I have had 3 different types of experience: provider met me in lobby and I rode up with her; provider who hid the key near the elevator (which I could not find, probably looking very odd rummaging through the planter in vain); provider saying you need to find a way up on your own (the planter lady finally asked me to do this). Any tips on how to shadow guests, convincing cover story, etc?  

...and never had a lady hide one for me to find. That just seems bizarre. I've also never had one tell me to find my own way up. If either of these cases occurred I would have left.  

and took it away.

...before the current requirement of having to show ID just to check in.

...but if it ever does come up I would ask the lady to meet me in the lobby so that we would ride up the elevator together (like mrfisher noted)

This hotel had two floors you could get on the elevator I meet her on the second floor which was not that busy. We got on the elevator and a gentlemen got on with us he got all nervous pushing wrong buttons looked like he was going to blow a wad right there wish I could have taken phone and taken a picture it was priceless.

I sympathize with the OP.  I don't know a good way around the key card problem.  

One of the reasons providers don't like to come out to meet folks is that they are already "dressed" for the date.  Also if they keep coming out on the hour to escort a new guy into the elevator, people might begin to talk.

I haven't been in a hotel with card access to the elevator, but wouldn't they have the same thing for the stairs -- at least main floor ingress.  I'm sure egress must be always allowed for fire code.

the locks have overrides in the event of a fire alarm.

for sharing your stories and thoughts. The approach suggested by Mr Fisher sounds discreet and promising.

Yikes!  Being in the technology field, I don't have a high degree of confidence that it'd function in every case.

This issue is overblown.  The best way to handle is to have the lady meet you in the lobby, or someplace nearby such as the hotel bar for a drink.  With an experienced lady, this won't be an issue.   It's only when you act unsure of yourself that you attract undue attention.  Playing hide and seek with hotel keys would be a way to do this.  Taking the stairs up probably wouldn't, though I would advise against it if it's more than say, four or five floors.

These days stairwells will have cameras in them of the type that set off an alert to security whenever someone enters them because ordinarily, hotels don't expect people to be in the stairwells and so when someone does enter, they figure they are either up to no good,or are in need of some kind of assistance.  Either way, you don't want to have a meeting with hotel security under any circumstances.

First of all, unless I am going to her home or to a hobby apartment or townhouse, I prefer outcall to avoid one obvious tried & true sting scenario.  The condo or apartment complex will either have clear approaches to the individual units or a way to get buzzed in.  If I am inviting her to my hotel, I scope out the entries, presence of key cards, etc and will suggest some of the approaches others have offered.  Another thing I try to do is to leave by a different entrance that the one I entered.  If I enter by the front lobby, I will look for a side exit to the parking lot so I don't go through the lobby again about an hour later.  If she visits me, I will suggest a back door for her to leave.