Good tips... but in reality if you're working full-time (especially in a software related role), you may find yourself depleted before you get to the keyboard. It took us 5 years to finish our game (everyone started from 0 knowledge on how to make games, so it was a rocky road), and for the last 1.5-2 years my life was absolute hell. I'd push hard at work for 9 hours a day, eat, then push hard on the side project for…
What I learned from other people who have success in their side projects is to choose a workplace that allows you to do a sub 40 hour work week. Of course you would have to live a tad more simply than your standard upper-middle class software guy.
Actually, many software jobs are like that. All it requires is for you to not be ambitious to create. You can have very good salary in many companies while slacking a lot. Sometimes you might have to be in office for a lot of hours, meaning doing leisure, socialization and side project in the office.