I'm "the AV guy" and have been working closely with your peers for decades. I'm going to write some blogs about issues we see / deal with, and hope it helps people improve their game. These will more focus on smaller (100-500 ppl) shows
Let's start before we even get to the stage - Dressing for Success.
There is a good chance that the techs will want to put a wireless lavalier/lapel mic on you. (Clients say they'll stay at the podium, but often move off to a side, sometimes walking clean away. )
Wireless lavs have belt-packs and mic elements
While this is usually not a problem with guys, it often is with the ladies.
There are two things to deal with - where to put the belt-pack and where to clip the mic itself. At an awards show last night we had a professional MC and she had us clip the pack to the back of her bra, but ladies like that are the exception, not the norm. I always feel bad for the girls whom we end up clipping it to the back of their dress, behind the neck, figuring the antenna must be distracting.
Also, women's blouses are often sheer (flimsy) and the weight of the mic itself, pulling on one side of the front, can make for some awkward looks...
Something with a cel phone sized pocket or belt of some sort solves the first issue, and something with a stiffer fabric/place to clip the mic itself to solves the second. Clipping the lav far off center does not work well, as your volume will fade in and out as you turn your head. Ideal placement is ~two ribs down, center. Final note with lav mics, necklaces can wreak havoc banging against the element. If you must, something that wont make noise/come in contact with the mic...
For guys, a jacket solves both problems. T shirts and gym shorts can be tough ... Button downs/polos are easy. Ideally, we'd clip it on a tie, but I have seen presenters balk, "This thing cost $600!"
Bottom line, if your look is very important, consider using a hand-held mic. More on actually using the mics on another blog.
Another thing to consider is to be careful wearing black. On smaller shows (100-500 ppl) you will often be in front of black drape with little or no back-lighting. IOW, your outfit can easily blend into the background and you become a floating/talking head. Bigger shows usually wont have this issue.
I hope this helps someone. If I think of anything to add on this subject of dress, I'll add it to comments below.
Thanks for reading and feel free to ask any questions about presentation technology, etc. I get it that your presentation is very important to you and enjoy helping people find success.