Outlook Desktop

1. Go to "File"

2. Then go to "Options" in the left menu bar

3. Then go to "Mail" in the left menu"

4. Then click "Stationery and Fonts"

5. Click the tab called "Email signature"

6. Click "New"

7. Type what you want your signature to be in the box below

8. Then in the drop downs in the top right for "Choose default signature" set this to the new one you have just created

Outlook Web

1. Click settings cog in the top right

2. Click view all outlook settings

3. Click compose and reply

4. Fill out your signature in the top box and tick the options below it