Bad question - false dichotomy - but here's some advice that's probably worth what you pay for it ...
Work on finishing things. Find a small project, start it, get feedback, improve it, then finish it.
It's the act of getting things done that will drive you to acquire the additional skills you need. You will be judged by your accomplishments, so make sure you have many to show.
Make your finished projects clean, clear, and usable. As you get better, tackle bigger challenges.
But here's the deal: Always be finishing them.
(Yes, sometimes things should be abandoned, but if you're doing that a lot, ask yourself why.)