What does the man mean by "DIY"?

F: What do you usually do in your spare time?
M: I like staying at home and DIY.
F: Woo! What do you do particularly?
M: I like to make some furniture and family decorations myself.
F: How did you come to like that?
M: Well, I once visited one of my friends. He did very well in decorating his own house. I came back and started my own decoration. It costs less. Now I am an expert.