Honestly?
A control to the top, a control to the bottom, a false shuffle, a false cut, a force, a steal, a palm, and a switch. You can probably create a version of nearly any card trick out there with that list.
The specific techniques aren't actually that important, whatever works best for you is what you'll end up settling into. Most professionals, as far as I can tell, don't actually use a huge range of sleights regularly. This belief is enforced when you read a bunch of books - it's largely all the same techniques just used with unique presentations.
That being said I see nothing wrong with practicing a large variety of sleights as long as the ones used in performance are kept to performance proficiency. There are several sleights I practice semi-regularly that I not only have never used in a performance, I have no intention of doing so. I practice them because they're fun. And keeping things fun is how you avoid burn out.
Now here's the catch - in order to find the sleights that work best for you, you're going to have to try a few different ones. Which means reading some books, watching videos, etc. Learning magic is an investment.
The most important thing, I think, to keep in mind is that consistency is far more deceptive than the fanciest or most difficult moves out there. So when choosing which sleights to use, it's important to make sure all of your actions are consistent throughout the performance. What I mean by that is that you want all of your actions throughout an entire performance to seem like they all go together. Mixing in a flourishy false cut for no reason other than it looks neat, when the rest of the performance has been fairly straight forward card handling, would throw up unconscious flags in the audience's mind.