I think it depends on the theme of the swap, really. There have been swaps where everything is out of my comfort zone, simply because what I'm making I haven't done before - my first few swaps were like that. Now, though, I think my comfort zone is expanding. I'm in a swap right now that is just one item, and I'm contemplating sending an extra that's way out of what I've done for a swap before. It's making me excited to try it, though!
That's one of the things I like about crafting for swaps - it pushes me to expand my skills.