Do: Get writing.
Every paper has a home. Sadly papers do not write themselves. If you don’t write it, no one else will. This applies at all stages of your career. The writing process clarifies ideas, identifies gaps and suggests key experiments. You may be doing the best research in the world, but work unpublished is effectively work undone. Knowing when to stop, when that one last experiment is not needed and it’s time to wrap up is critical. Careers falter on lack of publications and there are many roadblocks to getting your work published, don’t let one of those roadblocks be you.
Don’t: Aim for perfection.
Done is better than perfect. Yes the work has to be of a high standard, but no paper will ever hit perfection: aiming for this impossible goal will delay publication. I like to use the unlikely analogy of rifle cleaning. No matter how much you cleaned a rifle, the inspecting officer could always find hidden dirt: however, if you took it 90% clean, though they still found fault, but that fault was fixable. Ditto papers, even if ‘perfect’ the reviewers will always find fault. Better to leave a fixable hole and get published than get scooped aiming for the moon.