Wavedashing and dash-dancing are not mindgames. They are just tools for mindgames, just dash-dancing around randomly is no mindgame. It's just stupid, you'll get punished for it. Mindgames are basically.. hit=successful mindgame, don't get hit=successful mindgame. Hitting without getting hit. Wavedashing and dash-dancing is just a "confusing" way to move, but in my opinion it just gives you more mobility.
For example, as a Fox, you are really fast, and can do a lot of stuff very quickly. Against you is a Marth, against whom you have never played before. You run into his range, but quickly wavedash backwards. You see him F-Smash. run around and blaster spam and stuff to find out his attack and defence patterns, and what he does in different situations. Now, you noticed that he rarely grabs, and resorts to F-smash in almost every situation, except when you are above him, where he goes aerial or up-tilts. He will grab you if you keep on shielding, though. Run to him, shield. What do you think he will do? He might run to you and grab, if you think he will do that, predict and sidestep and punish. He might do something stupid like fsmash, shieldwavedash into grab into uthrow.
Find patterns in your opponent's game, predict what they are going to do, defend accordingly, counter-attack, keep on baiting stuff that you think they will do, find proper means of punishing everything, do what they don't expect you to do, do cheap stuff like blaster spam frequently if it annoys them, annoyed people are more stupid most of the time. For example, if you see that he likes to dash-dance into a grab, you can just run away and blaster spam, it will annoy them enough. Or just predict and punish, as always. Almost everything can be punished with Fox, he is fast enough for that. And it doesn't have to be laggy to be punished. Say, they just did a fair too far from you, and you have noticed that he likes to dtilt after the fair in this kind of situations. Think, how you can punish the down-tilt? If he likes to shield often, you might want to run towards him after his down-tilt, he will most likely shield or dodge. now this is, when you don't know what they will do, where you run behind their shield, and stop. Most people panic, and dodge, for whatever reason. If it works, use it, if not, don't use it. If they dodge, just punish with whatever combo is able to give you the most damage or the best result at the moment.
Mindgames are everywhere, endless, constant. They aren't just little tricks, every time you got hit you made an error, and you could have avoided the hit somehow. There always is room to improve. Only when you don't ever get hit in a match, are you good enough in mindgames.
