Blocker Tie Rings or a snaffle bit cut in half works. Horses can do a lot of damage to themselves if they sit back while tied. All my horses learn to give to pressure at a young age and learn to tie. But rarely do I tied off on something. I have cut too many horses out of messes they have gotten themselves into. I’ve replaced too many poles and tie rings on trailers. I may wrap the lead 2-3 times to give resistance as long as I can watch them. I never tie off on something if I am out of sight. Don’t get me wrong, they need to learn to tie. I just believe teaching them to stay is helpful as well. With the tie rings I can do that easily with young horses. I use a long rope and I put it through the tie ring and hold the other end to provide resistance. Eventually they learn to stay put with the slightest pressure. I use them in the barn and in the trailer. I use twine to attach the to a ring in the barn the twine will break quickly I use locking caribiners in the trailer. The locking ones prevent lips getting hung for those busy colts. I also use locking ones on my hay bags and buckets. I do have a few nosey horses that have to be tied off or they pull through the ring. Those are also the ones smart enough not to sit back.