I have endless tips, but I need to know who you are using! Even better if we can play a set so I can see what you do wrong. My FC is in mg profile if you want to add me. PM me yours.
If you are recovering, do not ever try to attack Bowser. Go to the ledge every time over recovering on the platform, unless you have a ranged tool to let you land safely. Any aerial attack, even without landing lag, can be punished by Fortress. Dodges also have recovery time when you land, so don't use those close to the stage.
Fortress (up B) is punishable if you block it, as well.
When Bowser gets close to you, I think it is generally best to go for grabs. Unless your attacks have more range than his.
K, thanks for the tips. I'll pm you my FC too
Fought someone who was using the Wario tech today.
Two-stocked him as DK
I played against some like that too, he just kept killing himself off the top of the screen.