Saving change seems to be a common tip here. I do that and it really helps (we pay most everything in cash so I get quite a lot of change.) Also, ROLL IT YOURSELF. There is no need to pay coinstar 9% to do something I can do w/ little effort while I watch a TV show.
Another thing I do is to save ones. It sounded hard at first but it's been really easy. Those add up quickly!
I budget a set amount for weekly needs (groceries, gas) and whatever isn't spent goes in the fund.
I basically work for our insurance. I have a piddly little check left when they take my premium out - I try to spend as little as possible of it and the rest goes in the fund.
Cut back outings - we don't need McDs 3x a week (sure, it's hard when I'm having a bad week and I'd rather feed the kids happy meals, skip clean up, and turn in early - you have to weigh the pros and cons, sometimes eating out is a sanity saver.) We rarely do movies but we did one last month and may do another this weekend. The trick? We now hit matinees and skip the concession stand!
If I have to order something online I use my Disney VISA. We had sworn of CC's but I got this one for the $200 offer and I never use it without the cash to pay it off. I put the money aside as I use it and pay it in full on the due date. I think I'll have an extra $20 or so "earned" over my $200 sign on bonus.
"Found Money" - for us that is any service that we usually pay for but end up doing ourselves. For instance, my cleaning lady hasn't been able to come for a month. So, I've been cleaning the house and tossing what I would've had to pay her in my fund. I used to take my car to the touchless wash and vacuum. Now I wash at home and put that $10-12 in the "fund".
I shop using rewards sites in addition to the Disney VISA. I have earned $75 in Landry's cards so far and have enough to cash out for $25 again.
I also do Swagbucks (just started this month but I'm almost at the cash out mark for my second $5
Amazon GC....these I'll save for Christmas.)
Buy Ahead (when it's on sale) - can't stress this enough. I hit huge sales starting in July of last year for this past Christmas. I am using coupons/sales to stock up for this year already. I also had Valentine's bought using TRU rewards dollars and Easter was purchased during post Christmas sales (mostly.)
Shop wisely for clothing - with three kids we need clothes/shoes every time we turn around. I shop places that reward me for shopping there and I try to combine a sale and a coupon. If I can get free shipping and do it online (through a rewards site) even better
Pack lunches - my kids pay $1.25 to eat at school ... which sounds cheap UNTIL you hear that there is little they like so then I have to buy snacks to get them through until supper. I pack a lunch for about what I'd spend on the school fare and they last until dinner

I also save leftovers and take for my lunch. It's $2 for me to eat so that is $10 a week I'm not spending.