How to download directly to ~/.drush folder? I've created a project that is basically a drush command with a starterkit folder. I noticed the make_local project will but I haven't figured out how it does that.

I've tried the approach recommended in the answers and added a .info file and tried to hide the .profile extension by renaming it to .profile.starterkit.  Drush still thinks I'm downloading a theme.
There are three requirements:


Your project must have a .info file
Your project must have a project.drush.inc file
Your project must not have a project.module file or any sort of .profile file


If all three of these are true, then Drush will store the project in ~/.drush. If there is a module file or a .profile, then Drush will treat the project like a module or installation profile (usually storing it in sites/all/modules).

Your project was missing a .info file, but unfortunately, the existence of the profile file caused Drush to decide that your project was an installation profile, and Drush thinks that those do not belong in ~/.drush.

The user will have to specify --destination=$HOME/.drush, or move your project to the correct folder manually.