Get a credit card with no annual fee (preferably one with 1% cash back). Pay absolutely everything with card (only rent/mortgage, loan payments, and utilities should be paid in a different way, and that's only because they don't accept credit card). Pay it off in full once every month (the same date every month, and only once a month) before the due date so you never give the credit card company anything more than the actual cost of what you bought.

This makes it incredibly easy to track your finances. Rent/mortgage and loan payments are fixed. If you make a steady monthly wage you know exactly how much money you are getting every month and exactly how much you have left for all non-loan expenditures. That number should be at least $100 more than you pay to the credit card to pay off your past month of living every month.

When you bank more than usual in a month you feel awesome. When you have to pay more than you made in a month you realize immediately and can take quick steps to curtail it.

This also gives you real-world data as to what living costs, helping you to avoid the planning fallacy.