Morning sickness hasn't kicked in yet, but with my last, brushing my teeth would trigger my gag reflex so badly, I would dry heave if I didn't have anything in my stomach. It got to a point that I would chug cold water because sometimes it would calm the gagging to stave off the heaving or I would vomit water, which honestly, was easier on me than dry heaving.
I would definitely recommend eating a few crackers before even getting out of bed, with something to drink, I am big "pusher" of coconut water. It's healthier than sugary soda, very hydrating, and can alleviate nausea and vomiting. Plus, it's high in potassium, which I know during my last pregnancy, the charlie horses at night were miserably awful and bananas upset my stomach so badly, I couldn't eat them.
When I was in culinary school, for my Nutrition class we had to formulate theoretical menus for case studies. Mine had severe hyperemesis, I had her drinking coconut water and sparkling water with lemon - which can also be soothing.