Cross stitching is a process of making tiny x's across a surface. The stitch size is standardized if you use canvas, or in our case soluble canvas making any surface work like canvas. Making it easy to get right, and because it's a two ply canvas, it cover the fabric well. Also cross stitch patterns of awesome geeky things, freely available all over the internet. Check out Starrley's (the creator of the Star Trek Com Badge pattern) other work if your short on inspiration. If you really can't find anything at all pick your favorite 8-64 bit character and give it a home on your clothing.
For the Star Trek Com Badge I used DMC Light Effects in the colors of E168 Silver, E317 Titanium, E3821 Light Gold, E3852 Dark Gold, and plain black. Available of at almost any craft store also available online here. Admittedly DMC Light Effects are usually $2.00 a skein, so it's understandable if you go for the plain embroidery thread which will only run you 99 cents.
Lastly here is the rank pattern, basic boxy circles with one plain square in between each.
Haven't seen the video tutorial yet? Well here it is: