One of the hardest balances I find for my writing is between the amounts of dialogue versus narration.
I like to keep a healthy amount of both inside my story, but I often feel like I lean one way more than the other when trying to find a balance. I either have dialogue without much detail, or a lot of detail with very little dialogue. It drives me nuts!
The largest part of the writing process for me is trying to get that balance and not the actual plot itself.