I've simply started using $GOPATH for everything. Even my non-Go projects live under $GOPATH/src/<url-to-repo> . I know many people are very particular about the way they work but I did not have any trouble adapting to this, and in the end I found it much easier to manage my projects.

My only problem now is that I have so many projects checked out that it's hard to remember which ones I am contributing to vs which ones were checked out as a dependency. I think I can address that by setting GOPATH to ~/thirdparty:$GOPATH or something, but it hasn't bothered me enough yet.