When you're playing Texas Hold'em, you may have the option of posting a straddle, but should you?
Now, whether or not you have in the past, consider a few things before answering:
1) In general, the answer is no. The only advantage straddling gives you is that you get to act last during the first round of betting. But you've put in a blind bet with no information and if you're raised, you're going to have to get dealt a pretty lucky hand to be able to call. It's a waste of money.
2) First exception: If you're playing a lower limit hold'em game than you'd like, straddling is a way to basically double the betting from the get-go. If you feel straddling takes players out of their "comfort zone" and will make the majority of players fold, it may work to your advantage.
3) Major Exception: If you're playing a game where a Mississippi Straddle is allowed, my advice is to always straddle. A Mississippi Straddle is when the player on the button is allowed to straddle, and gives you an enormous advantage, because you will have last position every single round.