I just made up envelopes for MYW tickets, food, and rental car.
I'm bringing home lunch 4 out of 5 days per week, savings to the "MYW" envelope.
I'm cutting back on junk food at the grocery store, all savings under my weekly grocery budget go to the "food" envelope.
I am also allowing myself to "steal" from the grocery budget for the 1 to 1 1/2 weeks that we'll be in Disney. That's another $100-$150.
Getting a whopping $.05 on cans and bottles

. I don't think that will even be enough to treat everyone to ice cream, but we're doing it for Disney.
We do the coin jar. My DH doesn't realize it, but 90% of the coins in there are from him. I usually tally it up before we travel and then announce, this ____, is on DH!" It also gives me evil pleasure to "steal" his money right out from under his nose!
I also have a set amount directly deposited to my savings at the credit union. That's for everything, not just Disney. I figure the vacation rental home will come from that savings.
My most important tip is to keep reading the budget boards for inspiration. It sure helps me.
Good luck!
