Malvolio is a "stuffed shirt" type of man.
He would be fastidious about his appearance and would spend time flossing just right. He would organize his sock drawer and hang the things in his closet in order. He also moons over Olivia somewhat, so he might plot to get her and to get the two troublemakers Sir Toby Belch and Andrew into trouble.
This is a great question! Here are some suggestions:
1. Iron undergarments and socks until they are stiff as dried concrete.
2. Write a diary entry. Write down word for word what my lady said, and analyze each comment in depth.
3. Set trap for Sir Toby
4. Make a to-do list (that's what an agenda is, but he is the type of person that would probably write in his agenda that he had to make a to-do list for his agenda)
5. Practice making faces in the mirror--so I can look stern yet sophisticated. Practice glowering at unwelcome guests and Sir Toby in the mirror as well.Try to get that suave yet disapproving stare down.
6. Style hair. Perfectly. Fix it so that the wind doesn't disturb it.
7. Buff and shine shoes until they shine like glass.
8. Practice diction so that I sound powerful and authoritative, and upper class. Not friendly. Work on speaking through the nose. Women love that.
9. Chastise the cooks for making the breakfast too hot/ cold or spicy/ bland. Bring my lady her breakfast. Be careful not to smile.
10. Dress up in borrowed robes and pretend I am a Count.