My biggest “hole” in my training (that I know of) is my knowledge of bits.  You explain pretty good about the snaffle bits.  I don’t have a couple grand to go out and buy a bunch of tom balding bits.  With that said what bits would you say are “must haves” and what do you stay away from?  The only snaffle I have is an old O ring that’s super heavy like literally probably 3lbs.  I worry it’s too much for most young horses.  I got it to soften up an old stiff rope horse years ago.  

When I do one rein stops or work on speed control by getting my 3 year old filly’s attention she has started to try to bite my foot.  I’ve kinda ignored it or just bend her the other way but every day it’s getting worse and not better.  Is this just an immaturity thing or is there some underlying issue, like could she be hurting?