Lanyards and T-shirts?
Yes we have done this on several of our cruises.
Many didnt wear the lanyards because they used the ones Disney gave them.
But the T-shirt we all wore the first day on board. Also wrist bands with the crusie date and name have been worn to recognise each other.
In the Terminal we started introducing ourselves because we would see a shirt and go over to the people and chat and by boarding time there were about 70+ of us off to one side talking.
We had several people stop us and ask if we were a family reunion. We said well we are family but we have never met before
We told them we decided we needed matching shirts so we could spot each other. We got some funny looks.

But then we explained we were Dis friends meeting for the first time.
By the time we met in the Promenade we had about 150 people including kids all dressed a like. We took a photo of all of us on the stairs.
Back then Shutters displayed photos on the walls and there were massive boarding photos together with everyone in the same shirt. You could hear people making nice comments about this huge family reunion on board.
A few didnt want to wear the shirt for their boarding photo but they did change after they boarded into their shirt.
We actually had a graphic artist in our group and he designed our shirts. We were the Bananaheads. We did 3 crusies together. I can ask him about the process if getting them printed if you're interested. I believe we used Cafe Press.
I do remember the more we ordered the less they cost.
It was set up where each family went to Cafe Press web site, found our shirt and ordered for their family so you paid for your own shirts and shipping and handling so nobody got stuck with the bill if someone changed their minds.
If you guys are really interested in doing this for our cruise let me know and I will ask Bill what the prodecure was to get them to do our shirts.
Kathy