I decided before I ever got my cat that I wanted to do clicker training with him. Mr. Davis is taking to it extremely well! One of the more recent things we were working on was having him jump up onto my wooden cube and wait there as I got his food for him - we've probably been at this for a little less than a week - me clicking and treating to get him up there, then clicking for him staying there for longer periods of time, then making the food and stopping to cue him back onto the cube and click and treat whenever he jumped down.
This morning, he meowed, jumped on the cube on his own, and watched me intently (and quietly) completely unprompted. He stayed there the whole time while I got his food, and waited until I said "Okay" to jump down, all without any clicks. I was so proud! It's super helpful, too, because he was one of those cats who twined around your legs while you were in the kitchen, making food preparation a treacherous occasion.
The biggest trick is figuring out the course of action to take to train him to do something, since it involves shaping tiny steps in the right direction. My current challenge is his morning "is it time to get up yet?" habit, which includes climbing up onto my chest, meowing in my ear, and putting his paw on my face. Since the idea being clicker training is that you reinforce behavior you want, and I can't very well bring the clicker and handful of treats to bed and spontaneously click when he's sleeping quietly, I will need a different strategy.
Other clicker skills I've taught him are "up" and "down" on cue, and to sit and let me put his harness on. Still working on a reliable "come," and a way for him to ask for me to play with him (his current strategy is to meow sadly and threaten the couch). Also, I'm teaching him to go into his crate, and to let me handle his paws so that I can clip his nails.