Some of mine are: reading 52 books, going for a walk at least once a week, getting a new piercing, and doing my budgeting every week instead of waiting multiple weeks, etc etc
What's everyone else's? Maybe comrades with similar goals can be accountability buddies 
I always recommend people to learn playing the guitar. It's relatively cheap, you just need to make one investment in the beginning. You can learn it by yourself using the resources from the internet or you can take a few lessons in the beginning. Learning to play it is relatively easy, you can make a lot of progress in just 2-3 months. Most of pop music is simple so you just need to learn some basic chords in order to play a lot of songs. Learning the guitar will make it easier to learn other instruments if you want. And of course you can then play in a band if you wish, which is the most fun part of it