You dont have to activly evoke these forces for them to take an interest in you. Once you get involved seriously in magick they can and some may decide to show an active interest in you. My experiences with Azazel has shown me this. He has popped up quite a few times in my life to point me towards useful info that helped me grow and i have yet to formally evoke him, likely to change this year 
Also this thread has alot of good info in general and some really good tips regarding how the results from evocation can develop