You go on the user's profile, and go below their "about me" information. It will show how to become their fan, report the user, and things like that. It will also say "Give fan props". Of course, you click that. You will pick what you want to give them props for, and then have the optional message to go with it. Then you send.
ok here is another simple way to do it obviously you go to there profile and when you get there you see the prop tab like the one on your page that takes you to the prop wall click on it that simple no scrolling down to give props just click the prop tab and write a message or not but remember to pick a prop to give.