I agree on the budget idea. I was just updating mine yesterday. I like to tag each expense with the account name that will pay it. I split my expenses to different accounts for different reasons, like shared expenses with my partner get paid from a joint account. I also think it's not fair to split joint expenses 50/50 because we make very different salaries so we split it according to the proportion of our post-tax income. So I have a formula that does all the math and then tells me how much money I need to deposit into the joint account each paycheck to cover those expenses, and same for my partner. I get paid twice a month whereas she gets paid every 2 weeks, so even if we split the bills 50/50 our deposit amounts per paycheck would be different.

It does a lot of other stuff too. This could all be done as quickly by hand the first time, but where spreadsheets really shine is reusing them later. Now, whenever I need to change an expense amount (prices for stuff change over time), add/remove expenses, or change income (which happens every year), all the info I need is recalculated instantly.