We go over anything and everything we can! We'll back for a good length of a trail. We work on pivots on the haunches and forehand, and side-passing. We also do those from the ground without any contact from me (and no holding onto reins/leadropes/etc). We work a LOT on whoa. He does it very well (I can ride him bridle-less and have him stop from a gallop) but we still practice it all. The. Time.
We open gates, we go through water, I mount him from trees or fences or tractors. We do a LOT of bonding. I'll hop off for a bit and just love on him and scratch the hard-to-reach places. Then we'll ride again!
Set the ground poles up in a box, and pivot in them. Then make an L-shape and side-pass and pivot over the L-shape. After, back through the L-shape!
I still do de-sensitizing things with him, even though he's now 11 and he's been putting up with me doing them for that many years! I think it makes for a good horse.
We trot and lope imaginary barrel patterns and lope and trot imaginary pole patterns (because I'm too lazy to set them up!)
We walk over jumps that are really high and hard to walk over.
After riding, we do in-hand things like showmanship. We back, pivot, sidepass, trot, walk and lope. I make him stand square and perk his ears up.
Pretty much anything I suddenly feel like doing, we do! You should, too!