Absolutely hate:
Tiled roofs. Paved streets. But most of all - cover illustrations. I really, really hate to draw covers. Don't because the actual drawing is any different than drawing a regular page, but because coming up with a decent cover-design that a.) works, b.) looks nice and c.) doesn't completely spoil the plot is incredibly difficult for me. And I'm just about to have to do it again before chapter five starts. D:
I used to be one of those people who disliked drawing environments and crowd-scenes, but I've done it so much now that I'm actually getting to the point of enjoying it. It's not something I go "Oh boy oh boy, I get to draw CROWDS!
" about, but it's no longer the huge, imposing obstacle it used to be.
Tip for crowd-scene issues - layer the crowd. Put your characters in the middle of it, and then draw some characters close up in the foreground, between your characters and the "camera", and then people behind your characters, and on the same visual plane as them, etc. Overlap them, to give the readers a sense that the characters are in the crowd, not in front of it. Also - it helps you block out inconvenient bodyparts you don't feel like drawing. XD
Example (with very grumpy cartoony faces!):
Love:
I love most of the comics-process, from initial brainstorming of ideas through thumbnails, sketching and inking and colouring. But I think my favourite steps are a.) inking characters and b.) colouring skin.