I started reading MMM several months ago. Prior to that we weren't too strict with anything. We luckily make enough money that we can afford to be a little "loose" but I was inspired by MMM to tighten the belt. So for about 6 months we just tracked our spending. Not a budget, per say, but at the end of each credit card cycle we would tally up all our purchases into some general categories.
Then 2 months ago we decided to try a true budget. By looking at how much we spent on eating on out and groceries, etc for the past 6 months we set some general parameters. And we're now using GoodBudget. Because it's free and pretty simple. Our finances, with two incomes, rental income, lots of different retirement funds, taxes, etc etc is just too complicated for YNAB.
We looked at our past spending and identified some categories we could use a bit more control. Those are eating out, groceries, and the dreaded "misc". (Unfortunately the rest of our spending categories are pretty fixed: housing, utilities, gas, cell phone bill, etc - unless we're willing to make some drastic changes, which we aren't.)
So at the beginning of each cc billing cycle we refill the envelopes with our budgeted amount of money. And for every purchase or trip to the grocery store, we log it into our smart phone linked apps. It definitely makes me take pause, and look a bit more closely at grocery store prices (should I get this at costco or giant?) , but let me tell you - the holidays was a horrible time to start! yikes. We haven't actually made it under yet. Still fighting the good fight and going to keep trying, though!
(learning some perhaps extremely obvious things - like, when the grocery budget gets low but the eating out budget is still okay - we could just transfer that money over and use it to buy a lot more groceries - duh, right?)