I write quite a bit, I have a laptop running Arch Linux (btw), and I use Scrivener for writing. It's a Windows app but it runs perfectly fine under Wine.

As for advice: sometimes I get caught up on the opening line, so to combat this I deliberately try to just write the worst opening line I can possibly think of. It gets it out of the way, and then whatever you write after that will feel like an improvement. Then you can just go back and fix it later once you know what the thing's actually about.