I think its pretty dang hard to underwater , but over watering you can do with your eyes closed and hands tied behind your back!

From what I hear you want your pots to be dam near bone dry between each watering to let oxygen get in and clean shit out / feed plants.

I have let mine get so dry I swear there isn't a drop of water in them, yet they have never really wilted. Just make sure when you do water, you PH your water! Learn from my mistake