Faith + Reason = Truth

The less destructive it is, the harder it is to give up.  If you gamble and bring financial ruin upon yourself, then it's obvious to you and to everyone you know that you need to stop.  If you fly into drunken rages or endanger people's lives when you drink, then clearly you have a problem recognized by many others.
Sometimes the vice is not so evil or wrong though.  Maybe it has caused you to miss out on something, or to act in a regrettable way, once or twice or several times over a period of years.  Maybe your most trusted loved ones and confidantes actually counsel you that you don't have an issue, as far as they can tell.  But deep down, it Is an issue for you.
That's a tough thing to give up.  But it may be even more meaningful to do so than one of the blindingly awful behaviors outlined above, since the only ones holding you accountable are yourself and God.  Oh, and since you may not be the sternest disciplinarian when it comes to yourself and your habits, you really do need to bring God into this conversation.  It makes all the difference!
If you want to strengthen your relationship with God and with yourself, try giving up something that other people really don't think that it's absolutely necessary for you to give up; try giving up something that, in fact, would be a bit baffling to your friends if they knew of your decision.  You can get a tiny sense of what that's like during Lent if you're Catholic, but to tell your Father that you're done, forever, with that thing, and to know that you are, has the potential to transform your life in ways that would never have occurred to you when you initially worked through the decision process.