Hello guys, ive searched all over youtube and im trying to figure out the best way of taking an original photo, possible black and white would be best to start with and then cutting a person from another photo and make the person seem like a legit part of the photo.

My aim is to get a famous person with myself stood next to them, possible with my arm around his shoulder or something. I seem to have the most problems with hair and getting the correct sizes for the people, the one its hard to get the imported one the same realtive size as the as the person in the real photo.

Any tips? Whats the best way to blend the "fake" person into the real pic?