It wont be worth while without proper equipment.
Go to a local T-shirt printing place, ask them for any defected screens 110 lines or higher and take it. Go home and clean it using thinner and rubbing alcohol. Wash it with soap and water and your done.
If you can, jack 110, 120, and 130 screens. the 110 is C grade hash, then B grade, then A grade...the best of the best.
This is for dry sieving BTW. You can convert them into DIY bubble bags if you want also.
Goodluck!