First of all, make sure you know the difference between loose-passive and loose-aggressive. Loose-passive means calling station. Loose-passives don't like to bet and raise - they like to check and call, so if you see a player like this suddenly wake up and start betting - RUN!!!!!!!!!!!! Loose-aggressive means they will raise before the flop with almost any 2 cards and will c-bet the flop nearly 100%, and perhaps even double/triple-barrel whether they hit the board or not.
Against loose-passive players, DON'T BLUFF, DON'T STEAL - EVER. Flop top pair or better and bet it. You'll win big pots more often than they suck out on you in the long run.
Against loose-aggressive players you have to be willing to ride the variance train. That's why people are recommending a bankroll of 20 to 30 and sometimes even 40 buyins. If a specific player at the table is raising 40% of his hands and c-betting 100% of them, he only has ONE STINKIN PAIR on the flop MAYBE 38% of the time - and that's *any* pair much less top pair. I'm not sure of the exact numbers but I think he only has one pair on the turn 44% of the time and one pair on the river 50% of the time. Obviously the board texture affects these percentages as well. It can make you look and/or feel silly if you call him down with a pair of aces and he just happens to have two pair or a set on that particular hand, but you have to understand that it's really hard to have something that beats top pair - you're going to get him to barrel off worse far more often than you're going to get trapped.
This article might help you if you haven't read it already:
http://forumserver.twoplustwo.com/32...43/?highlight=
Hope this helps
DTXCF
P.S. With regard to him hitting 2 pair on the river, you'll eventually get to the point where that doesn't even faze you. Seriously. Focus on getting your money in while you're ahead, not on whether or not the other guy sucks out on you.