I would suggest that you do as much research as you can on famous freestylers such as John Farnworth and Dan Magness. These guys are the absolute best that there is and you will learn heaps from these guys.

You can find these guys at:
http://www.johnfarnworth.com/
http://www.danmagness.com/

As the guy above says you should start off with simple juggling and getting a feel for ball control. You also need to try to get a consistent rhythm as well to make it easier. When practising you need to get into the zone and concentrate only on your freestyling. Avoid any distractions or background noise. If you become a professional you will need to get used to cameras going off and a noisy crowd which can easily put a person off.

Keep an eye out for blogs that discuss freestyling moves and tricks. Youtube is an obvious place to look for lot of videos as well. If you can find a local mentor to help you it will fast track your results considerably. There are freestyle classes in some parts of the world so try to search for those.

Best of luck,

Scott Dudley

http://www.howtolearnfreestylesoccer.com/
http://freestyle-soccer-tricks.blogspot.com/

Most of soccer is improvising. The most important thing for you to do is practice. Try just doing normal juggling until you've mastered it. Then make something up and repeat that until you've mastered it. As you get better, you'll find it easier to improvise.

Another very important way to learn is by watching professional soccer. Try going to games, watching on TV, or even using YouTube to watch clips of professionals.

Watch this guy: http://www.youtube.com/watch