Below are some useful keyboard shortcuts to save time when formatting documents. In addition to the keyboard shortcuts listed, many programs have a Paint Format feature that copies all of the formatting and applies that formatting to another selection of text.
Win/Mac
Ctrl/Cmd-B Bold
Ctrl/Cmd-I Italics
Ctrl/Cmd-U Underline
Ctrl/Cmd-X Cut
Ctrl/Cmd-C Copy
Ctrl/Cmd-V Paste
Ctrl/Cmd-Z Undo
Ctrl/Cmd-Y Repeat formatting
Ctrl/Cmd-K Insert a hyperlink
Ctrl-Alt-V/Ctrl-Cmd-V Paste special Microsoft
Ctrl-Shift-V/Cmd-Option-V Paste special Google