Commit messages should be in the present tense and describe what the commit does, not what you did. For example Fixes bug x, implements y opposed to Fixed bug x, implemented y.

The first line of the commit should give a brief idea of what the commit does and a detailed description of the changes should follow after a new line. Think of the first line as a title for the commit and the rest as the story of it. Something like the following:

Fixes crash when thing is done.

Fixes thing crash by adjusting when thing is done. This should still let other thing work when stuff gets moved.