Implied Odds, EV play, Etc.

[craiga_uk]

After having read lots of posts here, I see a lot of the replies go 'That was -EV play' or 'You should have put x amount in the pot for value'.

My question is - how do you guys work that out while you're playing? Are you all quick at the math, or do you use crib sheets/helper programs/etc?

Can anyone give me any advice and/or pointers please, as I think I pretty much understand the concept of 'Outs' and pot odds but I stuggle to apply them...

Craig