Draw a page of hands, eyes, noses, and ears. Create some realistic and some cartoony. Make sure that you're working with some form of reference; Google search is a great place to start.
Do some more work on your Jekyll and Hyde characters. I encourage you to publish your in-progress designs to the blog for feedback. You should be getting a feel for the story and background of your characters. Some questions to ask:
Where is your character from?
Why did this Jekyll person decide to start experimenting in the first place?
What were the ramifications of these experiments?
Is Hyde a better version of Jekyll, or an abomination?