I'm wondering how to continue to push the envelope - or more appropriately have it pushed - when sessions seem to be some variety of the same thing for the most part.  I love to have no idea what's coming and get my boundaries pushed, but it seems like there are only so many variations

If you are getting bored with the things you normally do, or ask for in a session, look around and find something that interests you but maybe scares  you a little, and ask for that the next time. Explain to your Dom what you've just said here, that you have found yourself looking for new experiences and XX or XX interest you, could she introduce you to them? You won't know how you will respond to these activities, you'll have to opportunity to change your mind and go with something familiar if you feel uncomfortable, and you might get a boundary or two pushed...plus you get to try something new that you just might love!! I find that when my CBT boys decide they are willing to try sounds, or my spankos are willing to try anal play, they find a whole new world of sensations to explore.

Whatever you do, DO NOT tell your prospective Dom "I want you to do whatever you wish, Mistress" !!

K

Some Domina's lack creativity.  I treat every client & session different because we all have desires that are not the same.

END OF MESSAGE

As nobody is a mind reader.  That said, my biggest challenge is things being to formulaic, and telling someone what I want both seems to defeat the purpose and also kills a major part of the thrill, which is truly not knowing what is going to happen.  So to me that feels like "topping fro the bottom" a bit

No, I'd like to know more?

I enjoy being  both dom and sub.  When I am with a domme who is really sensitive, I do not lay out my "wishes".  We have generally learned areas of interest and she then makes the choices with me almost never having to use a safe word.  
I also feel I have failed if my sub needs to use one.
The range includes who else might be present as audience or participant, what sort of scenes and sensations are included (I personally for example hate "medical scenes and the kind of intense sensations often involved at the edges. )
I don't like to lay out a scene as sub and I don't want my sub to have to do that when I am in charge

& start reading erotica to learn & push the envelope on your personal tastes

Working out of my home in Vegas (Bondassage) I found I was getting very routine and complacent---now I am back on the East coast, and I am stepping up my game.
I actually just set up an afternoon with a sub who is going to help me go more corporal- spanking, flogging, caning---I am finding different toy/tips n tricks, and expanding my sensual horizons as well as my biz model.
Hopefully I will be rolling with the private plane crowd soooon!

END OF MESSAGE

Madame Patricia shaved down ginger Root and use them as sounds... Check out her bag of tricks!
 Just an update

I had a partner that expanded my playlist.  He simply choose different things I had never done before that I was willing to try and we did those.  There were many types of play I discovered this way, and some I liked better than others, but at least I had tried it, I could explore what that type of play was about.

I found mind fuck play the hardest to get my head around.  I really thought this person is going to hurt me, not just "fuck with me" and scare the wits out of me.  It would take a really long time for me to get over thinking that person could be a real asshole at times.  And yet, I trusted that this person knew what they were doing and I kept playing.

And that's when I discovered it wasn't so much about the different sensations of play or types of play, but finding someone you really trust to play with, how golden that is.  With this person who can explore the deep edges, the taboos, and all the fun silly play.

You would need a BDSM Playlist, and you would need to go through it with the person you are playing with.  Not everyone is skilled in every type of play.  Providers vary in expertise.  Ask for references of your Top/Dom/Domme etc. that they have experience doing the play you want to explore.

Here is a check list on my site