Important: If you are going to work on the floor (as I often do, because I don't have lots of space) FIRST VACUUM!!! I had to learn the hard way - every hair or dust particle that is on the floor will cling to the sponge

Cut the sponge so that it looks like this

Draw spongebob's face, shirt, tie and trousers on the sponge.
Tip: test your pen on a piece of sponge scrap. I used a fineliner and when I started painting the ink started to smudge

Paint!

I laid some refuge bags underneath the sponge just to make sure the paint did not seep through to the carpet

Fold the sponge over itself where the dotted lines were and sew 1-2cm from the fold. I did the sewing on the inside, but if you sew on the outside, the costume might have a more rigid box shape

Fold the 2 flaps above spongebob's head over one another and sew them together. Then cut a hole, big enough to push your head through, at the top. Sew around the edges of the hole and the arm holes to make it a little bit more sturdy. I also glued some pieces of cardboard to the inside to act as shoulder pads.

And Viola!

Now find a groom and make him carve a house out of a pineapple and let him try and convince a real estate agent to sell his home