Squash my last X commits together using Git

Question

How can I squash my last X commits together into one commit using Git?

Answer 1

In addition to other excellent answers, I'd like to add how git rebase -i always confuses me with the commit order - older to newer one or vice versa? So this is my workflow:

1. git rebase -i HEAD~[N] , where N is the number of commits I want to join, starting from the most recent one. So git rebase -i HEAD~5 would mean "squash the last 5 commits into a new one";
2. the editor pops up, showing the list of commits I want to merge. Now they are displayed in reverse order: the older commit is on top. Mark as "squash" or "s" all the commits in there except the first/older one: it will be used as a starting point. Save and close the editor;
3. the editor pops up again with a default message for the new commit: change it to your needs, save and close. Squash completed!

Sources & additional reads: #1, #2.