Upcycle plastic containers (spray / detergent bottles) into baskets, gift bags, containers, etc. Maybe larger square gallon jugs for holding craft supplies or keeping small things together in the closet, or.
A tutorial for a plastic bag basket. Braiding, so no crocheting or knitting skills needed :) This would also work for making a nice shopping bag of all those single use grocery bags - just add handles. (Remember no bio degradable bags!