Sometime in the late 70's, I ordered a pattern from the Lincoln Enterprises mail order catalog, along with the Command Insignia patch. Then, my girlfriend(who is now my wife)'s mother made it from the pattern. We were actually able to find the rank braiding in the fabric store, and it looks exactly like what they used on the show. I wore it for a Halloween party. Because it was based on a so-called "official" pattern, and we were careful to buy the correct fabric, it looked very authentic, even though it's homemade. I just wore it with black slacks and black boots. I also had the AMT exploration set, phaser/tricorder/communicator, and brought that to the party as well.
I have no actual pics from that party, but I still have the tunic. Although, I doubt I could fit in it now.
Years later, my wife bought the first season TNG uniform pattern at a fabric store, and made one for me and my son(who was 8 at the time) and we both wore them when I took him out for trick-or-treat.
I still have both, but alas, probably cannot wear them, due to midlife expansion.