An executable file to open the sublime editor is already contained in Sublime directory. By default this is not added to your $PATH.
So add that executable file to one of the directory that included in $PATH.
$ ln -s /Applications/Sublime\ Text.app/Contents/SharedSupport/bin/subl /usr/local/bin/sublime
Here ‘/usr/local/bin/’ is present in my $PATH
Then take sublime as following:
$ sublime ~/projects/my-app
Here ‘~/projects/my-app’ is your app path.