I do the same. For me it's as simple as installing ~5 homebrew packages (I can get the same packages for my Linux machines), the Opera browser, and a copy of .bash_profile and .vimrc, which I keep in a Github repo. Having to migrate machines has made me trim down my development toolset significantly. I now know exactly what I need, and can go from fresh machine to the environment I'm accustomed to working with in < 1 hour.