Jumping ? Any tips?

Ok so today i want to try to jump , on my 16.2 HH standardbred(the one in my display pic). I have a small jump set up in the backyard that he and i jump for fun (but with a saddle). really isn't my thing so i don't do it that much. I can walk, jog, trot and pace on this particular standardbred. So what can help my balance and me to stay on while jumping? any tips are appreciated