We saw the "you are doubting yourself so much" and overthinking accusation, and now my own pet answer to many of your threads, Moongirl, (please imagine me fondly smiling and laughing at you like a friend, in a gentle way, I'm not being critical or jerky in my tone here, k?) ...it sure seems to me that you do a lot of asking how to communicate something, without having to talk about it. You know what I think about that, right?
OK enough of that, let's talk clothes.
I definitely agree with one sentiment that you brushed up against. Much like job interviews, I've found that on first dates, if I've done something that isn't typical for me and it's not comfortable, I'm gonna be more nervous and I won't come off the way I want to. I just won't be smooth and witty and good company. I'll be too busy fussing about my clothes or my hair. Hell, I might even have an unfortunate armpit sweat situation. All from dressing it up to a point that does not feel comfortable. That's not good.
So I've cultivated looks for those kinds of situations that work with the setting, but don't make me feel that way. And maybe more importantly, I don't do anything unusual with my hair, I don't wear makeup (I typically don't, and I find it uncomfortable) and I wear shoes that don't hurt. Beyond that, it's a question of context, how formal the setting is for instance, and which "me" I feel like being that day.
I can pull off "cute hippie chick" really well so that boho stuff rocks on me. I've got really long, wavy hippie hair that is parted in the middle and round glasses, so if I feel like being soft and gently pretty I do the long flowy skirts and such. Target has a brand I like, called Knox Rose, I've found some very nice "boho" style garments there. I have several pretty long gauzy scarves, I might throw on one of those. I have some form fitting ribbed turtlenecks that I can wear with layers, and give myself a "librarian" look. And believe it or not, at some point I decided to give a big middle finger to anyone who says I can't wear whatever I want even if it's a fashion from my gothy teen years, and I got some old pairs of Tripp pants. I've got a few pairs that are very loose fitting (not quite JNCO level bagginess, but baggy) though I pulled off the chains and straps, they have zippers and laces and metal doodads and stuff, and I will wear those with combat boots and a black metal band t shirt.
Yes, to a first date. With no makeup.
Actually I'm pretty sure I was wearing that the night I met my husband.
But for the most part, the impression I intend to make is going to happen in conversation or not at all. I don't ask my clothes to speak for me. I only ask that they cover me comfortably and do not distract me from talking to a (hopefully) interesting person. That is the one thing that I feel must be avoided at all costs. Clothing that makes you uncomfortable or nervous in any way. Rule numero uno.