One I used to like with my instructor looked like this...excuse my drawing skills...
So the red lines are the jumps and the green line is the track you follow. You can follow the track either way, recommended to try it both ways. So the point is to practice changing leads over fences and tight turns. So when you start this exercise you might do a 30 metre circle, slowly work those loops down tighter and tighter. Being a figure of eight this exercise just keeps going, great for building stamina too!
Often I just set up 3 or 4 jumps in the arena, so if it was joined by a line it would be a zig zag, so you go over the first jump which is on a diagonal, then the next jump in on the other diagonal, if that makes sence, other then that I don't know how to explain it.
You could also set up 3 or 4 jumps and make a mini-course.
Make some scarey jumps! This is great fun plus it teaches your horse to jump whatever you ask.
Put a rug over the jump
Attach plastic bags to the wings
Use random stuff from round the yard (safe stuff only) I.e. Hay bales, tarps to make them look weird
Make crooked jumps I.e. Top rail is sloping to one side
Water jumps (my mare is convinced water jumps are a breeding ground for piranhas!)