PRE-FLOP
The size of the pot usually dictates the level of your bet or raise. In early position, a bet of 75% to 125% of the pot value will scare off most limpers, and is probably low enough for you to bail without serious injury to your stack if you're re-raised by a player in late position. (In that re-raise situation, unless you're reading a bluff or you have a great hand of your own, it's okay to bail out and fight another day!)
In late position, raising or re-raising from three to six times the amount of the pot will spell that you're serious and should cause most weaker hands to fold (and is therefore a potentially effective bluff/semi-bluff tactic).
POST-FLOP
In 10-player games, where your strategy should be tight, don't call with medium-strength hands. Unless you strongly suspect a bluff or the player is clearly on tilt (playing emotionally due to a recent bad beat, for example), maintaining your discipline and folding to a strong bet will pay off even if you're holding bottom or middle pair.
