How do you handle table selection & knowing when to leave a profitable game?

[Scorpion Girl]

So how do you actually decide which table to sit at when you've got options? Do you look for specific player types or skill levels or is it more about the overall vibe? And here's the tricky part when you're already in a game and it's profitable, how do you know when it's time to walk away? Like do you have a set profit goal and just leave once you hit it Or do you stay longer if the game is really good even if you're already up?