I have a single spreadsheet with fairly simple formulas for calculating monthly expenses based on average recurring bills vs. (after tax) salary income.

I can see generally what my "discretionary" balance should be and that gets spent on food, stuff, etc.

Things that are recurring: Mortgage, Utilities (take annual average if you can), services, savings, etc.

Use savings like any other bill - a certain amount must be paid/deposited every month. Use automatic balance transfers from checking->savings on payday to facilitate.

I don't try to get too fancy with it and heavily leverage automatic bill pay for making sure I can't forget anything.

Check all your accounts regularly. For me that's a weekend task to do with my morning coffee. Check account balances, make sure credit accounts are addressed as needed, review investments if applicable, but don't freak out about them.

I'm partial to treating investments as long term gambles that are NOT something I'm relying on for retirement. It's just something else to slowly build up over the long run that might be something that can help later or pass on.