If one has a certain amount of funds in their budget each month, one can set a maximum number one can spend up to that amount. For example, if one has $1000 budgeted for one month, keep a record, with receipts. One can spend it on anything. But one must consider food, gas and other purchases. This is good for people who have advanced knowledge in finances.
If one desires to put this into a more structured budget, they can make half of their budget into set amounts of spending and the rest open air. But once that $1000 is spent, one has to wait until the next month to spend more money. If one spends over their budget, it will effect the following months budget. Use cash only.
Here is how it works: take out a sheet of paper and write down how much one desires to spend each month. Then write all of the months spending (rent, car, gas, food, medical bills, and retirement fund and any debt). And one can spend anything above that at their discretion. But it may be good to save as well. On the topic of using cash or credit cards, one should only use one or the other. Some enjoy using cash only and others like to see what they spent on when the billing statement arrives in the mail each month to keep track of it. So, in the example, each month one has a monthly budget of $1000. Out of this, one must account for all of their spending and savings. After all of this, anything in excess can be spent on with leisure.