The use of the imperative, present tense is one that takes a little getting used to. When I started mentioning it, it was met with resistance. Usually along the lines of “The commit message records what I have done”. But, Git is a distributed version control system where there are potentially many places to get changes from. Rather than writing messages that say what you’ve done; consider these messages as the instructions for what applying the commit will do. Rather than having a commit with the title:Renamed the iVars and removed the common prefix.
Have one like this:Rename the iVars to remove the common prefix.
Which tells someone what applying the commit will do, rather than what you did. Also, if you look at your repository history you will see that the Git generated messages are written in this tense as well - “Merge” not “Merged”, “Rebase” not “Rebased” so writing in the same tense keeps things consistent. It feels strange at first but it does make sense (testimonials available upon application) and eventually becomes natural.