Some favourites of mine are:
Using code sections/chunks – Use Ctrl+Shift+R to insert a code section and a popup box will appear for you to name that section. Ctrl+Alt+T runs the current code section. When you are done working on a code section you can ‘fold’ it up to improve the readability of your file (Alt+L is fold current code section, Alt+O is fold all sections).
Re-running code quickly – Ctrl + Shift + P will execute the same region of code that was just previously run with the changes made since then.
Deleting/moving stuff faster – Ctrl+D deletes an entire line. Ctrl + backspace deletes the current word as in most word processing software. Alt + up/down moves code up and down lines in the console while Shift+Alt+up/down copies lines up/down.
Switch between plots – To toggle between plots use Ctrl+Shift+PgUp/PgDn (It’s a lot faster than using the arrows above the plots!)