It’s really easy to show your geek colours as a knitter/crocheter. Changing the colours of things or adding a tiny bit of detail here and there. It can also be a great start in learning to adapt patterns.
Two years ago my husband asked for a Star Trek TNG Engineering jumper. I agreed assuming that there would be a pattern out there. Well, you know the saying about assuming! So, I had to create one myself. I found a pattern that had side panels (Redford by Julie Hoover) so that took care of some of the colour work which left the black shapes at the top and bottom to sort out. Armed with my stitch and row gauge and some graph paper I set to. The hardest part was getting the colour to line up on the sleeves and the front and back. But it turned out pretty well.
This year I finally made my own Start Trek TNG cardigan. The wonderful striped job worn by Wesley Crusher. Again I found a basic pattern (Macaulay Cardigan by Katie Green) and added in the colour work. This time round a wonderful person on Ravelry had already done the chart for the left sleeve so all I had to do was make everything line up.
I love making small alterations like this. It really personalises a garment and it is more straightforward then you think. So be brave. The worst that can happen is a bit of frogging ^_^