You don't have to abide by everything the guy says, but I like a lot of the ideas over at https://www.mrmoneymustache.com/ in terms of living frugally.

The ultimate form of freedom is being able to decide what you want to do with your time. One way of accomplishing that is making a ridiculous amount of money via a successful exit. Another way is to structure your life so that you're ok with less. Sure, I think most would prefer the 'have lots of money' option, but 1) even there it's easy to get sucked into spending more, as this article mentions, and 2) we have a lot more control over living frugally while earning well (most software engineers earn pretty good money) than we do over a wildly successful exit from a startup.