Sorting your change. Just empty your pockets and sort your change into each compartment.

Organize your  buttons, safety pins, bobbins, snaps, thread and other small items on your sewing table and craft table.

Store your Christmas ornaments by placing an ornament in each compartment, close and secure the top.

Use your egg carton to start a fire.  Just place a torn egg carton under your firewood as a fire starter.

Start your plant seedlings using the compartments of an egg carton.  Place some soil and a seed in each compartment, place in a sunny window and water as needed. When your plants are ready to plant in the garden, just cut each section out with scissors and plant in soil.

Use your egg carton as a paint pallet for kids. Just squeeze a paint color in each section.

Travel helper. Pack small items in each compartment of an egg carton and place in your luggage bag.

Give your egg cartons to a chicken farmer.  You may have someone in your neighborhood who raises chickens, they could sure use some egg cartons.

Check out these egg carton lamps.  They are really neat!

Cats seem to really like to lay on an egg carton.  If you have a cat,  cut a carton in half and let him play with it.

As for the fast food tray, do as I do.  When the fast food attendant hands you your drinks in a tray, take the drinks out, place them in your car and hand the tray back.  If you need to take the tray home, be sure to recycle it with your mixed paper. Reduce, Reuse, Recycle.