It's just a piece of fabric you wrap around your waist as many times as it will go, then tuck the end in. However, women's sarong skirts are generally sewn into a tube.

I'm a farang so I only wear mine indoors, instead of PJs. If you plan on wearing yours in public, I would recommend not going commando.

Thai Farmer Sarong
 

Having long been fascinated by this comfortable looking garment I have purchased the necessary fabrics to make/wear one. Is there anyone out there with instructions on how to tie this garment and exactly what I need to put one together other than the fabric itself.

Actually there is a special way of tying it at the front, but its difficult to explain. Best to get a Thai to demonstrate for you.