Shortcuts are really useful and make you gain productivity, here are those I use or force me to use:

Eclipse:

Inside file operations

Move line(s) Alt + (Up || Down)
Duplicate line(s) Ctrl + Alt + (Up || Down)
Move inside a file without moving cursor Ctrl + (Up || Down),
then Up || Down to go back to cursor position.
Quickly move cursor inline Ctrl + (Left || Right)
Move cursor to line begin or end End / Begin
Text selection Shift + ( Up || Down || Left || Right )
Quick text selection Ctrl + Shift + (Left || Right)
Comment/Uncomment line(s) Ctrl + Shift + C

Switching files operations

Search inside a file Ctrl + F,
then Enter to switch,
then Echap to edit last selected one.
Search inside a project/folder Click on project/folder inside Eclipse explorer,
then Ctrl + H,
then Ctrl + (. || ,) to switch.
Open a file from opened projects Ctrl + Shift + R,
then type file you want or things like ‘AbstractListing*.js’,
then Up || Down,
then Enter.
Go to prev/next opened file Ctrl + (Page Up || Page Down)

Firefox / Chrome:

Open new tab Ctrl + T
Close current tab (Mouse middle click too) Ctrl + W
Reopen last closed tab Ctrl + Shift + T
Go to prev/next tab Ctrl + (Page Up || Page Down)
Go to specific tab Ctrl + (1 || 2 || 3…. || 8)
Go to last tab Ctrl + 9
Go inside url field F6
Modify zoom Ctrl + (+ || - || 0 (reset))
Reload, reload without cache F5 / Ctrl + F5
Open developer tools F12