Map bills to paycheck windows, not just the month
If you get paid on the 1st and 15th, or every other Friday, divide your bills roughly into two groups: bills covered by the first paycheck and bills covered by the second. This is a quick check that neither window is overloaded before you spend anything discretionary. If one window looks crowded, some non-fixed bills can often be moved to a different due date by calling the biller.