I am pretty happy with http://cushionapp.com/

I learned a lot about design by working closely with designers. You could visit your favourite websites and try to figure out what makes them great. Observe and re-apply the things you saw. Do not blindly copy them. Basically, it's the same as with code: If you just copy code you might have a working app/site but you won't get better at coding. Anyway, you answered you question almost by yourself: "using sketch" - just design something, find a client who needs a (simple) website. If you can't find any take an existing/fake company and try to re-design their website. And most importantly: keep at it, you will get better every time you open up sketch (photoshop or that new hot app xyz). As resources I would recommend: https://abookapart.com/products/design-is-a-job (great source of inspiration) https://hackdesign.org/ (weekly email to get you off the ground)