I'm not sure who told you that black magic is the most advanced method of practice but they were wrong. In all varieties, the development and understanding and knowledge is pretty in depth. Gauging which is the "most advanced" is rather impossible.
That being said, the invocation or evocation of demons is not always done for "black" purposes. Many such methods involve overcoming one's own sins and so forth, and not merely seeking favors from them. The way in which demons are viewed also varies from tradition to tradition, with Judeo-Christian influenced traditions often viewing them as utterly evil, many more modern pagan traditions viewing them with caution, and other paths exploring them as benevolent spirits.
When you have explored the methods, and understand the different views of it on your own, you will be ready to evoke a demon.