Gmail hack: know these simple keyboard shortcuts

First, enable them: go to Settings > Advanced > Custom keyboard shortcuts > Enable > Save Changes. Here are the ones that will save you the most time:
‘c’ allows you to compose a new message
‘r’ replies to the message sender
‘s’ will add or remove a star to a message or conversation
‘f’ will forward a message.
Clicking ‘tab’ then ‘enter’ will send your message.
If you want to create your own, open the Keyboard Shortcuts tab in Settings and configure your own.
Don’t make these keyboard shortcuts that make web browsing 10 times easier.
Gmail hack: check your email offline

Google allows you to check your email even when you’re not hooked up to WiFi. Just go to Settings > Offline > Check Enable offline mail > Save changes.
Gmail hack: schedule an email to send

If you’re working late one night and don’t want to bother your co-workers but are nervous you might forget to send the email in the morning, Gmail lets you schedule emails to send in the future. Instead of clicking the blue Send button, click the arrow next to it and hit Schedule send. This box will pop up that allows you to select pre-selected times from Gmail or pick your own.