If you really wanna....step on up and get on your apron cause this is gonna get messy! You'll need a few things...golf balls, a board..hot glue..LOTS OF PAPER...and finally a small, fine mesh hand strainer from the kitchen.
First..go find about a dozen golf balls and hot glue them to a board in a nice 6x6 pattern with about an 1/8 to 1/4 of an inch between them. Be sure to use a big board because again...this is gonna get messy! Also..cover the whole thing with plastic wrap for easy removal...be sure to work it down in between the golf balls.
Second....take a large pot and fill it full of paper...any kind of paper..from newspaper, copier paper...junk mail (take out the plastic windows)...just fill that sucker up...then fill it full of hot water and wait a while. (it helps if you shred the paper first...blender, leaf shredder...doesn't matter)
Sooner or later the fibers in the paper will soften and let go. Stir it up and add more paper...let it sit till it is liquidy again. Keep doing this till you have a thick pulpy mess the consistancy of thin pudding. Now..use the hand strainer and pull it through the pulp. You're gonna get a big wet soggy mess...plop that down over the golf balls and mold it around them, all the way to the board and in between.
Now comes the hard part...waiting! Here is the science of what is happening. At the microscopic level, those paper fibers look like they're made of rough poles covered in fish hooks...As they dry, they tangle together, making one solid whole. This is the same process that makes paper..except after removing the pulp from the water..the pulp is run through heated presses to make it dry alot quicker.
Once it is dry, check to see if it is thick enough. You want about an 1/8 of an inch. about ... that thick. If it isn't, pull out more pulp and mold it over the first set and let dry again.
If it is dry..then gently ease it off the balls. If you used the plastic wrap this is pretty easy. And there you have it..homemade egg cartons. I know they don't have a top...but they still work...and they are handmade! Set them outside for about a week...they'll get stiffer each day.
Don't know if you want to do that much work...but there you go!