First off, cook your bacon either in the oven or on the stove until crispy and the pan is sizzling with grease. 

If your bacon grease is already hardened and cold, place it into a large measuring cup with a spout, and microwave it for 1 minute or until it is just melted. If it is already melted, make sure it has cooled to a temperature that will not melt or damage your egg carton.

Pour some of the bacon greases into each of the sections of the egg carton. They should be filled about ¾ of the way to the top.

Place the filled egg carton into the freezer for 30 minutes, and allow the bacon grease to harden.

Pop the individual bacon grease seasonings out of the egg carton sections, and place them into a Ziploc bag or other airtight container. Store in the freezer, and use as needed in the amount needed for each recipe.