Not only is practice important, but so is making sure you are doing techniques in a way that makes sense. This may seem trivial, but I see newer players do things like this all the time.
Here is a common example: When dashing forward and wanting to wavedash forward afterwards, don't put the stick back in neutral. You are already holding for example, right on the analog stick. Simple take the stick and nudge it downwards into down-right. Some people will put the stick in neutral before the wavedash. Why add the extra step? It may have something to do with the way they practiced. Similar to waveshines, some players will put the stick back in neutral after the shine. Why do that when you are already holding down and the next input is down-right? Doing things the easy way will work wonders for your clean inputs.