I don't think there is a method to it : as a developer you should see a lot of opportunities to automate things in your daily life. If not you probably need some hobbies outside the dev world.

I started coding about 10 years ago because I wanted to make a better bot for World Of Warcraft than what was available. Literally if it wasn't for WOW and an obnoxious coder that wouldn't share his bot code I wouldn't be a developer today !

Among more recent projects, I made a "green" script to encode videos at night while electricity is cheaper, a tool to extract, rename and classify rared / ziped nested ebooks (obtained from dubious sources ;-), another tool to analyze and optimize my chances at winning on football (soccer) bets (let me say it didn't work very well).