I love my datebook and take it with me everywhere. One thing I've found to be really helpful is to do my budgeting in my datebook. I'll pencil in what I want to spend at each event (ex: happy hour with the office ($15) or dinner date ($30)). I tend to blow my budget by overbooking expensive social events. This way, if I'm looking at an expensive week, I'll try to commit to fewer things or cheaper get-togethers the following week--a walk or catching up at someone's house. Also, having an idea of how much I plan to spend before events out (especially ones including alcohol), make me more likely to stick to my budgeted amount (or even try to beat it by spending less!)