Find a suitable image of your starship. My preference is for the NCC-1701 from Star Trek: TOS. The pose of the ship will determine how you need to aim the lasers.
Find a suitable image of the starfleet crew badge.
I will not include any of the images for download since they are easy to search for.
Print it out onto a fabric page or an iron on transfer sheet.
Follow directions on how to do the iron on transfer. These were iron on transfers for dark fabric so you had to print a non-mirrored image, peel off, and then iron on. I used a piece of cooking parchment paper as the protective sheet to iron on the transfers.
Cut a piece of iron on fusible interfacing that is about the size of the starship saucer. Hold the shirt up to the light and position on the inside so you can reinforce the area where you will cut to mount the laser module.