my usual method of screen printing involves making frames from strips of wood and stretching printing mesh around it, then cutting a stencil from vinyl and applying it to the back of the screen. this method is cheap, almost foolproof and gives you a lot of room for making changes and making multiple screens at the same time. the downfall of this method is that it can only cut a certain complexity of design, as if it is too complex the stencil isn't small enough to pick it up.
the 'proper' way to screen print involves using acetate print-outs of the artwork and an aluminium screen that has emulsion coated over it. the artwork is placed over the screen and uv light is passed through so that the emulsion below the 'black line' art dissolves in the screen and the image is 'permanently' held within the mesh until washed out with chemicals.
this method can print incredibly highly detailed drawings and images which look much more professional and clean than the stencil method, though it is expensive so i only use it on images which i feel really need it. below shows one of my two a2 aluminium screens which i have just got developed with new artwork