I'm a naturally frugal person and always just watched my account values at the end of the month. I wrote down my income and my bills, along with estimated spending (groceries, gas, etc), to see what I should have left each month. I wanted to see the account grow by $1k (example). So, if one month it was only up by $600, I either overspent or had something expensive come up. So the next month I would actively try to spend less. Worked great for then purposes.
I ended up purchasing the old YNAB when it was on sale. I wanted to make sure I was doing everything I could to maximize savings for a new house, and to help my son with college, but still have some money for fun stuff like vacations. I was also facing a decent pay cut in order to escape a hellish work environment, as well as losing child support (it went directly to my son when he turned 18).
I've been actively tracking and budgeting for about three years now. I like to look and see exactly what I've set aside for my son for college, as well as the new house, and see how fast I can make the house numbers larger. I've got my cash spread around where I can earn as much interest as possible (which isn't much right now), so it's set to bank/credit union limits rather than the amount I have for each goal. It does help keep my spending in check, even though it was never bad, just because I really want to be able to move more money into those more important categories. When I work overtime, I add a little for fun stuff, and a lot toward the house.
Once my son is done with school and the house is built, I'll probably do away with the down-to-the-penny stuff, and go back to what I did before. If my YNAB crashes before then, and I can't get it working again, I won't go to the subscription program, I'll just do a spreadsheet. But, for now, it's worth it.