A few things first, as well as a screen and squeegee and your chosen colour of paint, you will also need brown paper, a sharp craft knife and some scotch tape. You'll also need to have some kind of plan as to what you want to print and something to print it on. I'm starting the Christmas pressies, so I've been working on canvas tote bags. Really lovely to print, and I know they'll get some use. After deciding my design, I copied it on to the shiny side of the brown paper, and then cut it out. Sounds simple yeah?
It is really, just don't do what I did and cut it like you were cutting out the shape - cut away all the paper, leaving the shape I wanted to print. THAT was embarrassing - especially as Mr O pointed it out to me, I didn't realise I had done so and was cutting out the intricate design totally wrong *sigh*. Also if copying a design I find it useful to trace it into paper, then tape that to your brown paper and cut both sheets at once.
Make sure your blade is sharp, and I recommend taping your paper to your cutting board, especially if doing something intricate. If you do make a tiny mistake, all is not lost as you can tape it up as I have with the one below.
Tape your screen - this is basically what it looks like, tape around the edges with scotch tape - it protects the sides and make sure there is no spillage outside of the stencil. Pop your item on some paper -just in case- and if using a bag pop a sheet inside too so you only print one side, then place your stencil on top and then your screen on top of that.
BE GENEROUS with the paint, more is better than less, as you can scoop what is left on the screen back into the pot. Plop a line along the stop of the design, hold your squeegee at about a 45 degree angle and pull it toward you, across the stencil. If you need to, scrape the paint off the squeegee and do another pass, making sure you've covered the whole design. Mind those edges I missed them on one of mine!!
If you do miss spots, you can fill in lightly with the same ink and a brush (I should have mentioned brush in the equipment list doh!!), and you can use the same technique to fill in any bits you couldn't cut out, like I have on the "J", to get a seamless print. As you can see from the photo below, it looked different before its date with the paintbrush.
You can, of course, print another colour on top when its dry. On the "J", which is for my mother-in-law who loves purple, I've filled in with a metallic purple fabric paint, and I've got ideas for adding buttons or sequins to another design. Depending on your paint, you'll probably have to "set" the paint with the iron once its dry, which I recommend doing before you sew or glue on any bling. Read the instructions on the paint, and then add another minute for luck, it won't hurt.