Labels to put your name on everything or super sharp sharpies to write your name... things do get mixed up accidently and it avoids hurt feelings.
Wet wipes/germix/kleenex for your sewing area.
Tylenol, extra glasses or contacts if you wear them
Slippers & Robe ( I always forget them )
"Business Cards" with your contact name/number to hand out
CAMERA & batteries
Chargers for everything
Bottle water
Map / GPS / Directions / Reservations
Pictures of family / projects
One Dollar bills & coins
Big trash bag because nothing ever fits on the way home back the way you had it.
Have fun