You know how it goes. You tell yourself this is the month you're finally going to save more. Then life happens the way it always does: the mortgage, utilities, groceries, a dinner out here and there, the everyday little purchases that never feel like a big deal in the moment.

Then the end of the month rolls around, and you look at what's left.

The problem with saving whatever is left is that "whatever's left" can look wildly different from one month to the next. A good month might leave you $500 to save. A rough one might leave $100 — or nothing at all.

One of the simplest ways to build better financial habits is to flip the order: save first, spend what's left. Automate the whole thing, and you stop having to make that decision every single month.

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