Dorms are notoriously tiny. And shared. Don't clutter it up.
1. Duplicates of items you only ever use one of.
Most people don't use more than one backpack, pair of sunglasses, or nearly identical black t-shirt. Take your favorites.
2. More “mugs” than you will use between washes.
I use about three or four mugs before I wash them. But I own 10+. Your "mugs" could be shoes, clothes, accessories, etc. It's basically anything you own multiples of but still only use three to five of on a regular basis.
3. Fun reading books.
College is crazy, and friends almost always want to hang out, so time for reading doesn't really happen. If you do end up with a lighter semester or just want that nostalgia of a good book, your school's library probably has it. Or even the local library in the community might have what you are looking for. You don't have to clutter up your dorm room for the occasional read.
4. The above kind of goes for any hobby.
Unless you are majoring in said hobby or even taking classes in it, you probably don't need your entire set for said hobby. Take a few small things that don't take up much space but still allow you to dabble in the hobby when you feel the need.
5. An entire set of cooking things.
Most colleges and universities require you to have a meal plan if you live on campus. You are paying for it so use it.
6. Large furniture.
Dorms are small and already have furniture. Things like butterfly chairs, plastic sets of drawers, and ottomans can be handy and add a touch of comfort to your room. But it's wise to wait until you move in to determine just how much room you have.
7. Things you don’t use.
Now this is broad. But really, if you don't use it now, you probably won't use it at college either. So don't take it.
Take what you use. Leave what you don't. Think minimalism.