What I have read in a book, what works for me, and what I tell any and all of my students is, "braid loose, pull tight". That works on both flat and round.
Many people tend to pull harder with the strong hand than with the weak hand. I tend to be the opposite if I think about pulling when I braid. I know that sounds funny. I had braided about 40 feet on a reata and my rawhide instructor looked at it and asked, "How do you braid so even?" I asked her what she ment and when she explained about the lines being straight i noticed it. Since then, if I think about pulling even, I always pull harder with my weak hand. Yes, I am kind of odd.
My point is, practice, ask questions, listen to advice and take all you see, hear and learn and use the best that works for you and throw out the stuff that doesn't work.