I think that's the key - you do it via bootstrapping, and you DON'T kid yourself that you're building the next Apple Computer in your garage. As long as you keep your goals reasonable, it's hard to tell yourself that stupid sacrifices are worth it. (Most people would spend a year in Antartica with no phone for $AppleFounder, but would likely not do it for $moderate income, for an exaggerated example).
But be constantly aware that your main "customer" in your life is your spouse, and then kids. People put up with a lot without making it clear, often.
Someone as an outside observer who can tell you that you're starting to screw things up and you will listen can be incredibly valuable, both for the startup and for the family.