How Do You Guys Budget Yourselves and Keep to It?

I budget our money. We always have money left over at end of the month. I know how much goes out on the mortgage, bills and groceries and when the time comes I always look to change suppliers to get a better deal. I know how much we have left after all our necessities and our sons playgroup have been paid. Then we put aside an amount that can be spent on 'luxuries' such as takeaways, eating out. The rest is then saved.

I budget by working out my average income (I'm not on a salary income) and then working out my outgoings (bills etc) and seeing how much I've got left. I then work out how much of that I want to try to save and how much I need/want left over to spend