You have probably heard of one of the most famous street doodlers of the last few years (and possibly ever). He went from being a Bristol artist to an international phenomenon, for his political and social comments via the medium of graffiti art. While Banksy's images would have at one time been a seen as community vandalism or as a sign of a poverty stricken area, his style and vision has in fact made his work a source of pride for any place where he has put ink to concrete. His pieces are either instantly registered as national treasures or sold for a lot of money. This may have given you the idea that you might like to be a graffiti artist too. Here are a few tips on how:
Learn how to paint
First thing you need to do is to learn how to paint. Anyone can be a vandal: taking a marker pen or some spray paint and drawing rude messages or football slogans on bus stops, but if you want to be a real graffiti artist you need to know how to draw, paint, sculpt at a reasonable level and be able to deliver some sort of valid message through your work.
Get your own angle
With this in mind it is good to develop your own distinctive style of graffiti. It might be a particular colour scheme, it might be what you target for delivering your messages or a recurring theme in your work. Banksy for instance uses stencilling for speed and likes to deliver messages criticising government and institutions while referencing pop culture.
Understand that it is illegal
Having said all this, it is important that you remember that no matter how beautiful and bold your statement is, in the eyes of the law it will be classes as vandalism. While it may be important to you that your work appears daubed across the front of Buckingham Palace you may have to settle for a wall in a studio or somewhere that will give you permission. They may even provide you with art supplies like canvases and craft kits and things to help you plan though and this would be especially helpful if you were just starting out.
One thing that has helped Banksy, and not just from a legal perspective, is keeping his identity a secret. You may want to do this too if you have any concerns about getting into trouble, but if you're going to do this legally then you shouldn't have anything to worry about.