Fundamentals. I keep my expenses low and my income high, if i can. My job affords me a neat little side-gig, so i use that as my fun budget. Then my wage can easily pay for necessities and leave plenty of extra to put away. Rent is low, too.
At some point soon, i'll start setting up proper plans. I've already started setting up a roth ira, and i have a 401k through work i'm putting a part of my paycheck in. I will want to get a new car at some point, so i want a bit of money in my main account for that, but i have enough to start a decent roth ira, i think.