Matthew Timothy Bradley is posting a series of blog on field-garb, which is both very useful for those in or going to the field and is also very amusing. Some good analysis from, of course, a field anthropologist. Here are a few quotes, and do follow his blog (linked above to Matthew’s name) to find out about good and bad rags for the field.
Most of the rags here in Burundi come from the vibrant used clothing market – in which all items are carefully and well washed and pressed. A good way to go; just this morning I passed a fellow and his friend along the route, each with a stack of jeans slung across his shoulder, off to a nearby village to seek purchasers.
In the States I always purchased from the Banana Republic, which, until bought out by The Gap, stocked loose, fully cotton, and generally conservative clothing items and accessories that were (and still are) excellent styles for the Middle East and Africa.

Drying loops on garments are useful. Or you could also just use the belt loops. Source> http://savageminds.org/2014/04/27/fieldwork_clothes_ii/
This is intended as the first in a short series of how-to posts for optimizing your clothing choices for the heat and humidity. The individual posts will be organized around a particular type of garment or gear, such as outwear and footwear. This post will discuss undergarments and headwear and neckwear …
This is an anthropology blog, so archaeologists and primatologists are obviously within the scope of the intended audience here. Environment rather than discipline is the determiner. The information is equally applicable to linguists, geographers, geologists, ecologists, and anyone else planning fieldwork in swampy or arid conditions. …
… keep in mind when planning your budgeting and packing priorities that the natural anti-microbial properties of wool mean you are obliged to wash merino underwear less often. (And by all means, do wash your own underwear. Even if you hire out your laundry duties, it’s just good manners, and don’t be surprised if it is an expectation at your field site.)
Source – Savage Minds, What the Well Dressed Field Worker is wearing this summer.