Use a bath mat...


...Just not this one.  Want to cover an old bench but don't know a good upholsterer?  Maybe you don't want to spend a lot on custom upholstery?   Try covering the existing cushion with a long bathmat.  You can use hot glue or fabric glue to attach the mat.  Don't have an existing cushion?  Purchase a twin size memory foam mattress pad and and cut it to size.  This is a quick fix to a pain in the ass... no cushion that is.  This is one more way you can Pull It Together.