When playing pocket pairs I use the following rules for any pair 10's and under. Preflop I will limp if possible, but will call up to a 5x bb raise so long as the raiser has more than 20x bb in his remaining stack. If I limp and someone goes nuts and bumps it to anything more than 5x the bb I will fold.

Any pair over 10's get a raise preflop. The amount of the raise depends on the table, players, and feel. If I think I will get a player to call with a weaker hand for 6x the bb, then that's what it is. If I raise preflop and miss the flop my actions depends on the table. If it's a passive table that likes to check call my actions are defined. If it's a weak table that folds to pressure I have a course of action to follow. If it's an aggressive table that likes the check raise my actions are different still.

I've found that the best way to accumulate chips in both tournament and cash poker it to keep your opponents guessing. Don't play pocket 5's the same every time, change your style up with each occurrence.