How much removal should I run?

I play at my local LGS (not as much anymore) and with my usual playgroup. Both areas are fairly casual as I don't enjoy CEDH game (yes I've tried it, just wasn't for me). I'm just wondering what is enough removal. I've heard everything from 4-12 is enough. I want my decks to be good where I can play at any LGS and not run into issues.