• Initial commits should be as small as possible. you should avoid putting to much into it. (blackhole)
• Write commit messages for your reader. Commit messages should express what changes were made, in a way readers can follow easily.
• Write concise commit summaries, commit messages should be around 50 characters.
• Commits should be atomic, if a commit changed more stuff it should be put into separate commits.
• Add the context of the commit into the commit message e.g add links to issues and stackoverflow answers.
• Use git add -p to add changes separately to the next commit.
• Separate changes from refactoring, by adding a hint to the commit message. e.g. git commit -m "refactoring: my commit message
• Use git commit --amend to edit last commit
• Interactive rebasing is cool git rebase -i.