The easiest place to start is in Science and/or Social Studies. If you need a starting point, begin with doing some demonstrations with just a few volunteers coming up to assist. This means the mess is contained to one area, but the students are still taking a more passive path of learning.
If you want to step it up a bit, make the lessons hands on. Let the kids do the complete demos on their own. This works great in stations set up around the classroom and students divided into small groups. If you're students aren't used to this you will need to train them how to simple work as a group and clean up before they move on. It's so worth it for a bit of magic and pizazz that your students will really remember.
HERE is a place I wrote a bit about a specific set of hands on learning.
Where might you add some magic to your lessons this year?
How can you keep it simple with the focus on learning?
Have some fun with this one! If you enjoy the magic, it will be contagious to your students!