Create a design on paper. Simple shapes with straight lines, such as squares or triangles placed in a random or measured-out formation, are a good starting point. Cut these shapes out with a craft knife. This creates a paper stencil. When creating your design, remember that you will have to cut it out, so don't choose shapes that will be very difficult to cut.
Tape the edges on the underside of the screen with masking tape. The underside of the screen is the part that will be touching the fabric. Place your paper design on the underside of the screen and cover all of the exposed mesh with masking tape, but do not tape the stencil to the mesh. In other words, any mesh not covered by your paper stencil should be covered with tape. This will stop the ink from leaking around the edges of your design.
Get your T-shirt and lay it flat. Place your paper stencil on the part of the T-shirt where you want the design printed. You do not want to secure the stencil to your T-shirt as it will be difficult to remove later. Place the screen on top of the stencil. Try not to move the paper design while lining up the edges of the screen and the design.
Place a tablespoon of ink at the top center of the screen. Use the squeegee in one hand to pull the ink down the screen, while holding on to the screen firmly with the other.
Pull the ink down the screen one more time and place the squeegee to one side. Try not to drop any ink on to other parts of the T-shirt. If you do drip ink on other areas of the T-shirt, water based ink can be removed with your regular detergent and water if the spill is addressed instantly.
Hold the fabric with one hand and pull the screen up with the other hand, pulling from the bottom edge of the design. The stencil will come away with the screen and leave the T-shirt with its new design.
Repeat the design by placing the screen on another T-shirt and pulling the squeegee down the screen. There is no need to clean the screen or re-apply more ink. If you are finished or the ink is beginning to dry, wash the screen. Water based ink will be very hard to remove from the screen after it has dried.