The other techniques are shield dropping, wave landing, wall and ledge teching shffling, meteor cancelling, wall jump, and more. There are some more that could exist that could be exclusive to your character like fox/falco have multishine and samus has super wavedash. There are also more movement options like dance dancing fox trotting and more. What I found useful was going to pewpewu's channel. He's a top Marth player if you didn't know. A good way to practice is to first go into training mode and trying to do the technique. Something that i found useful was putting the game on 1/4 , 1/2, and increasing it to 2/3 until i could do it at regular speed (however this is only for the ones that require you to do something in very specific timing or very quickly). After you can do it in practice mode, go to vs and play a lv 1 com and 99 stocks with infinite time. Then try to learn how to incorporate it into your gameplay and practice against an actual opponent.
