Our main item we'll need is a 18 gallon tub here are the dimensions on the one I used if yours measures the same dimensions as on the picture you will have a very similar result from mine using this download template available here.

Prep the tub by cutting the rope handles and the gusset supports around the handles, here I am using a Dremel 200 and a cutting disk. A dremel is a rotatory tool which is very versatile.