Some ideas:

1. Pick something that you want to build

2. Pick something new that you have wanted to learn

3. Use 2 to build 1

4. Have a specific goal, and keep working X minutes a day - absolutely no matter what.

5. Ship

Time actually runs fast, and even if you spent just about 60 minutes a day, you will quickly realize that you can squeeze in almost a working day into a week.

It's quite powerful, and before you know it you would have racked up a lot of knowledge, and actually have stuff to show.