I usually get cels of characters I love.
Sometimes, I'll get one of a series I don't know 
because I really like the way it looks.
I got this cel from a random series since the 
art reminded me of Yoshitaka Amano. 

I generally prefer characteristic shots-shots 
that really show a character's personality.  
Otherwise, I prefer 3/4 view shoulders up 
shots that show the character's entire head. I 
hate it when it gets a bit clipped at the top!