A nice, even racetrack pattern is a good ptactice (the "routine" landing pattern at most fields). From there a horizontal figure-of-eight at a constant altitude. Not as easy as it sounds. Then, big, as close to perfect loops. Anyone can jamb the stick back and do a loop. A 15 or 20 second loop that is nice and circular is a little harder.

Split esse - Roll the model to inverted and then feed in up elevator (which takes the plane down) and bring the plane back in the recripical heading. An elegant way to reverse course.

A half-loop and half-roll. The opposite of the above. (aka Half-Immelman). A way to gain altitude while reversing course. Travel level afterwards and then do a split esse back down and you've dome an Immelman. Originally a way to evade and then attack a following aircraft and a fun maneuver to fly.

Spins you might want an experienced buddy on hand for the first few. Some trainers will not spin. Some spin well. Rarely you'll find one that will flat spin, or do an inverted flat spin. Not everyone has a "trainer" they are learning on. Some planes do not recover from spins well. Some not at all.

Stalls - get 200 fet up and throttle back until the plane stops flying while you try to hold altitude. There's more danger you'll konk the engine at idle than the stall will be a problem for a trainer. Some models snap suddenly to one side. VERY good to know how slow is too low for your model. Finding out for the first time at 10 feet above the runway is not good.

Cuban 8, inverted Cuban 8. Good to practice. If you've got enough horsepower they are easy and fun.

And as others have said: landings, landings, landings. The whole flight can be ferschimmel but if you land well you'll still be happy afterwards.