Another great technique is looking back on your life and find some peak experiences. "Start with why" is a pretty cool course to go through, but you could also just reflect on your own. Find your best experiences, and do similar things.
A lot of time I spent my weekends doing datastructures and algo. It seems at that time that I am learning but there too I didn't see myself making any progress it resets every time I take a break of a week or two and I myself admit that I am not persistent in any of my choices on what to do on weekends. I work in a 6 day job here. So I got only one day, i am working on my efficiency and try to put myself in place where I can make some quantifiable amount of progress. But yeah happy to here that weekends are the way to assess and do new things.
Don't use a library then. Do it all yourself manually, go through all the headaches. Then look at a library and see how they did it, pain is good soil for learning.
When you do things the wrong way, experience the pain ( the reason they are wrong ), and then you discover the right way, you really learn the lesson.
This is also the deep route ( doing everything manually without libraries ). So I'd suggest depth.
If you just want someone to tell you a framework: use nodejs, knex.js(mysql), express; react, redux, react-router, immutable-js, reselect
Are you a blogger? Write your own blogging software so you don't have to deal with Wordpress and ton of plugins, build something tailor made for you.
That's just an example but I recommend choosing something which will benefit you personally as a weekend project otherwise it might be difficult to motivate yourself to finish it.