Don't over submit or be market/sales-y
Pique HN's curiousity
Keep in mind most submissions get little attention
Check out previous show hn's to look for patterns, try searching for similar submissions, read comments
It may be worthwhile to get a feel for HN but lurking and reading stories & comments more generally
Do not ask others to upvote or comment
Play the long game, submit blog posts showing how to do cool things with your project, add respectful and relevant comments with links to your project, always keep int mind that HN is full of curious learners and dislikes sales / marketing, generally speaking