If you haven’t already, install Vimium and go mouse free. After a few days of training, your productivity will go up dramatically. Basically, Vimium makes every link in Chrome a keyboard shortcut – a powerful tool to speed up your online productivity.
One issue I had was that Vimium was disabled by default on Gmail. Gmail has many internal keyboard shortcuts, but I have a couple of Gmail extensions that don’t support shortcuts. By installing Vimium I was able to add shortcuts inside Gmail to those extensions.
Inside the Vimium documentation a reference on how to configure Gmail to work with all of the internal shortcuts plus Vimium. But, that page didn’t come up with a Google search.
So, to configure Vimium to work with Gmail (where Gmail shortcuts are on):

Here is the list of keys to insert into the KEYS field:
?jknpxercgils#uld/
Make sure Gmail keyboard shortcuts are enabled.