Lastly, if the numbers still aren’t adding up, you can look at adjusting your fixed expenses. Doing so will be much more difficult and require greater discipline, but on close inspection a "need" may just be a “hard to part with.” Such decisions come with big trade_offs, so make sure you carefully weigh your options. Tip: Small savings can add up to a lot of money, so don’t overlook the little stuff. You might be surprised at how much extra money you accumulate by making one minor adjustment at a time.
Finally, do it again. After you have completed your first month of budgeting, it will be easier to plan for the next month. At the end of the month look at how you spent and make adjustments for categories in which you spent more than you planned, and cut back on the categories that had additional funds in them.