>>211Writing long, meaningful posts is pointless if no one is going to read them. If you already have an audience, be my guest, but it usually makes more sense to do things when people are already paying attention to you.
My advice would be to associate yourself with highly visible individuals, events and occurrences.
If you can, take a picture with one of their idols/leaders while wearing one of your shirts. But before you take the picture, give the person a free shirt, he will appreciate the gesture and seem genuinely happy to pose with you (resulting in a good picture that will get more exposure). Perhaps that person will later be seen wearing said shirt, but of course this will only matter if your product is easily recognizable and found for purchase.
For events, try to take part in the organization of conferences or meet-ups, and offer some of your shirts as gifts for speakers or prizes for whatever.
There are also polarizing occurrences, which are good situations to write those posts you mentioned. When a subject that has a lot to do with the groups ideology comes up, be the first to post something relevant. It would be especially advantageous if it was a negative situation for the group, in which case you can claim how outraged you are. I think open letters are "in" right now, so that's a thought. Try creating a hashtag or associating yourself with an existing one as soon as possible after the occurrence.
Naturally, you should try to apply all of these techniques simultaneously.