I'd be happy if I could stay on track with planned purchases only for 2012. For part of 2011, I kept a spreadsheet with items, price estimates, and anticipated purchase dates (just the month). Unfortunately, it totally fell apart at some point and I didn't really get back on track.
Smaller purchases get a little trickier, like what happens if something from Uniqlo that I'd like to try out pops up on B&S, or there's a sale on something that I've had in the back of my mind for a while but I haven't put on the list or included in my budget? Should concert t-shirts count when they're at least as much a souvenir as an article of clothing? Do I set aside an additional discretionary fund if my planned purchase for that month isn't particularly large?
Most - if not all - of my larger, planned purchases can be delayed, so it's also harder to resist something at a lower priority level but with limited availability.