If you are looking to improve your Gmail productivity, the first place to start is with keyboard shortcuts. Never using your mouse or trackpad to navigate Gmail is the biggest time saver you can do.

First, you need to enable keyboard shortcuts in the Gmail SETTINGS menu.
Screen Shot 2017-04-14 at 2.40.16 PM

Master these top commands:

c - compose new mail
j - go to previous mail
k - go to next mail
e - archive (goes to All Mail)
r - reply
gi - go to inbox
ga - go to all mail
gd - go to drafts
l - label
gl - go to label

Full list of shortcuts here