Oh my I have soooooo been there! So....here's my list of places/things to use...when available of course! Amazing how the horse can adjust to these quickly and to your benefit.
rocks/boulders are better
ditches/stream banks - horse
stands in it and you hop on him
from the bank
car bumpers/truck beds/trailer wheel
Wood fences/metal gates-takes some
jumps of any kind
trashcans/turned over buckets/muck
wood piles/rock walls
Natural things out on the trail are readily available in my area. If you don't see anything; just lead your horse down the trail and you'll find a downed tree or stump or hill or stream or something. There's always something!
I bought one of these used and haven't been able to find a way to make it work for my mare and I. I have Spastic Diplegia, so when I lift my leg up to mount, if it is higher than perpendicular to my hip I have no power to push up.
The EZ mount doesn't drop the distance enough for us (Cay is 16.1). I should find it a new home, but I keep forgetting.
Thus, if I have to get down away from the barn I have to find something and something TALL.