Ever had a great idea turn into your worst loss? Usually it wasn't the idea. It was the size.
Set your MIN and MAX before the trade, by asset class. Equities run 2% to 6% per position. Fixed Income 3% to 10%. Commodities 1% to 4%. Longs always larger than shorts.
Then scale inside those lines in 50-150bps increments. Never a full position in one move.
Full cheat sheet below. Learn the rest of the process at