It is so cheap and so, so easy! It just took a little time, and it's probably the best thing I've spent money on for our hobby.
Marguerita McManus has videos up on Youtube showing the tutorial for it. You custom build it for your sewing machine! So perfect.
https://youtu.be/g14govA4pIM
She did a couple videos on it - I can't remember if you actually need to watch them all or not, but I did. You may not be able to find the super thick blue insulation that she used. I think the thickest they had at my home improvement store was maybe 1.25 inches? I can't remember now, but it's this purple/pink color with the pink panther on it
I got the vinyl covering at my local big box store for a couple bucks. It was supposed to be a table protector/table cloth type thing. I used packing tape to tape it down around my foam so that the edges were covered. Just like wrapping a present.