Make everything as portable as possible.   It may have been a while since your child has had to share a bathroom and/or not had a bathroom attached to their bedroom.  Here are some tip

1. Have a basket for transporting all shower items from their room to the bathroom. The basket should have ventilation so it will dry out and not get moldy.

Make it portable

Use a well ventilated container

Shower organizer that hooks on the shower bar

2. In some residence the students need to supply toilet paper.  Extra can be stored under the bed. Send all shower essentials shampoo, conditioner, soap, shaving, etc in a convenient portable size.

Use under the bed storage for extra supplies

3. The basket may include an over the doors hook that the student can use to hang their towel while showering so it is convenient.

4. Send a bathrobe.  They may not use one at home but might find it useful at residence.  Pack one that they will wear not one that has been around for a long time.

5. Send 2 bath sheets and 2 or 3 hand towels and 2 washcloths.