I have done a few, I used laminate floor underlay foam, the white stuff on a roll from B and Q, 2 or 3 layers, spray carpet glue.
The suede I used was cut out of the back of a sofa, quite thick, I stuck it on with a hot glue gun, melted my fingers a bit!!
I used some old leather jacket too, was a bit easier as it was softer, but I doubt it would be as hard wearing.
I always stop and hack lumps out of abandoned sofas at the kerbside/dump. you never know when it'll be needed!!
Good luck, its not that hard!!
MM