Martingale also entails luck + huge capital to begin win.
For techniques, I usually go max bet or a least with a decent multiple when I start to play slots. I don't know, maybe I felt that in the beginning it's better to go like this and if you are lucky then you can win big right away.
Just last Saturday I went to a landbase casino and just play 2 games, slots and roulette and very lucky to win in the beginning because of the max bet that I did on a slot game.
Martingale strategy is one of the best strategies to get a good your deposit back, but this game technique is too much expensive because of course doubling your lose capital makes a chance to win and get back the funds or else losing more double than your previous wage, but I did the same strategy too in other slot games and make a good profit but I end up keeping those winnings than make another risk of double the funds.