Grids help a lot with control and don’t need a lot of standards
Jumping jess (on youtube) has a small pouch for her phone that she attaches to the back of her breeches (on the belt area). It is great, doesn’t bother the horse (some horses spook at phones). I plan on getting one soon. I will update my comment shortly once I find out the name and brand of the pouch.
I recomend you to work with smaller jumps and short gymnastics that make the horse think more.
You can do a lot of exercices such as small obstacles, mechanization lignes (especially in the diagonale to have more space) for the balance, just one vertical to work on the height and the approach (diagonally), you can work on tight curves by jumping on a circle or on the serpentine, you can also work on the direction by using small poles and have tight fences.
I hope i could give you some ideas, good luck :)