You’ve surely seen these homemade signs erected by worried child-carers. But just imagine all the other possibilities for some wood attached to a post and installed in the ground … And we’ve never heard of anyone getting arrested for this.

Bike lanes are a relatively popular and easy DIY project, but, as always, watch out for cars.

Parklets — little pop-up parks in self-contained parking spaces — actually started as do-it-yourself urbanism in San Francisco. Since then they have been adopted by groups and municipalities on a temporary basis in cities around the country. But just because The Man co-opted these little hang-out spots doesn’t mean you still can’t DIY. If you’re going for a long-term parking space occupation, though, just make sure to feed the meter and lock up your goods at night.

It’s cute when artists make projects out of potholes, but what if we, you know, fixed them instead? Cities put significant resources behind pothole-filling blitzes, but that doesn’t mean you can’t DIY with the right supplies. (Between this and the bike lanes, you’ll make so many new grateful friends on two wheels!)

The gutsiest guerilla gardening moves involve heavy power tools and a lot of, well, spirit. If you don’t have either, seed bombs are cool too, and still of marginal legality, so you can feel like a badass either way.

City hacking: It’s good for you, good for your neighbors, and fun — when you don’t get caught! But remember, DIY infrastructure could cost you a pretty penny, and even land you in jail like poor Anthony Cardenas. It can also be a gateway drug to bigger political action.