The lady who is boarding our horse will pay my husband to make some horse obstacles for her, ideally with junk she has sitting around the farm (e.g. old tires, old 4x4s, random lumber, old pallets, and whatever other random junk is out there). Does anyone have any advice for this? Particularly, since we are new to the idea of obstacles, are there some things that he DEFINITELY needs to not do. For instance, I thought that when you were making a pole to jump that the pole should sit loosely on top of the risers so it would fall off and absorb the impact, rather than the horse absorbing the impact, but that doesn't seem to be the case. I would love some ideas on obstacles that he could make, but even more so some ideas on what he should NOT do, for safety's sake. Thanks!