Burlap is something you can buy at a local thread and/or fabric store.
You can order pre-cut burlap strings or jute (I use burlap.)
Or, you could buy just regular rolls of burlap and then cut them up.
Then you tie it onto the netting on your ghillie suit.
And if you are cheap, I can tell you are going to buy a pre-made ghillie suit.