This Halloween my department at work is dressing up as Star Trek characters. Being the crafty person that I am, I was tasked with making our commbadges (or combadges - I've seen both spellings). Here's my DIY tutorial. Bonus, I used my old business cards and sharpies, so it was a SUPER cheap craft.
Gold, Silver and Black sharpies
Old business cards (4-5 cards for an original series badge; 8-9 cards for a The Next Generation badge)
Not Pictured - hot glue gun
Step 1: Glue four business cards together with the glue stick.
Step 2: Create a pattern. I sketched this several times before I was happy with the shape. On this online tutorial, the crafter traced the pattern from a picture on her computer. In my research, I found that the badges are supposed to be 2''x2''. Basically, it should look something like what's pictured below with the skinny "leg" on the right.
Step 3: Trace and cut out your badge.
Step 4: Color the edges of the badge with a black sharpie or marker.
Step 5: Color the back and front of the badge with a silver sharpie or marker.
(You can always order a patch from Lynellen (above etsy link), if you want to skip the DIY part. They look really cool and are well-priced.)
Draw the symbol on an extra business card and cut it out. Color the edges black and
Step 6a (continued): Glue the symbol onto the middle of the front of your badge. Here are the badges I made from the original series:
Step 7: Using your hot glue gun (glue stick doesn't work as well over the gold and silver sharpie), add a little dot of glue on the back of your badge.
Press the safety pin into the glue and overlay a small square of business card. Press firmly.
I added the character's name and the year for fun, since it's a group costume. I don't expect anyone to keep their badges forever, but if they are sentimental (like me), it's nice to have a reference.
There you go! All done! I hope this tutorial was helpful, since I found very few on the interwebs.
Just for reference, if you want other perspectives on such a project, I also found the following tutorial which clued me in that the "legs" of the arrow are different sizes, even though I think she has hers backwards. She also used paint instead of sharpie, which is probably faster if you are mass-producing them.