First of all, shout out to Nicole for talking this through with me :)
I have been brainstorming ways to keep track of your expenses/money without writing anything down. The more I am meet people and talk about this whole budgeting / family financial management things, the more I am realizing how different people are when it comes to their finances.
What about those people who hate writing things down, what's a good way for them to track their expenses. What I've come up with is a three bank account method. One savings account and two checking accounts. The savings account is for (obviously) saving. I would recommend having part of your paycheck automatically deposited into savings so you are not even tempted to spend it.
As for the two checking accounts, one would be for bills like rent, utilities, loan payments, cable bill, cell phone bill, etc. Everything that is a "pretty much fixed" expense comes out of this account, however food/household expenses should not come out of this account because there is a higher risk you'll overspend here and you won't want to be taking away from your bills. Food/household items should come out of your second checking account a long with everything else. Yes I just said everything else. Since you already know you're saving money and you've got funds available in your other checking account for bills then you can spend this account on whatever you want. No writing anything down, no keeping track of all the details. As long as you keep your account at a comfortable amount (as in you're not risking overdraft fees) then feel free to go out for coffee, buy that cute dress or catch the latest movie your friends.
For these two accounts, along with your savings account I would have a percentage of your paycheck automatically deposited into each account. Or, set up automatic transfers with your bank, whatever works best for you.
This is the simplest way I can think of to keep track of your spending, while still being responsible, but also still having room for an impulse buy if you do so desire.
Note: as always I am not a financial expert, I am simply sharing an idea. I, personally have never even tried this idea but I'm just sharing it because maybe it will help (or inspire) someone out there on the world wide web.