I would say these are some general rules for all games and gamblingd, not only sports betting. Managing risk, having patientce and cool head as well as to know your limits is something every gambler should have on its mind but in practice things often turn out very different. Knowing yourself and your own psychology is very important if you are gambler.
Knowing yourself couldn't help if you break your own rules, mate. When I said these things, I said them because I have followed them myself and the major part that I forgot to add is (I'll be adding the below para right now in OP):
Have an edge over yourselfIt's not funny to gamble tbh, some people do it for fun but where's smartness in losing your money? Will you be called smart? No, right? It's better to only use and invest your bankroll in those games over which you have an edge. If you are sure about the game you are betting, then only use your 1 unit on that game, otherwise no need to gamble based on half (or 0) knowledge because we are talking about smart gambling and managing our bankroll. This assures that you have higher chances of winning over losing, and this edge will only help you gaining much more profits in the long run. If you don't know about a game, or yours is a few days ahead, just don't gamble and wait some days and let your expected game arrive.