So let's get a bit personal here and talk about underwear!
Travel Underwear
Yes there is such a thing as travel underwear! When I first started traveling, I quickly learned to bring only non-cotton quick-drying underwear. Then I discovered performance underwear and was sold on them immediately.My boyfriend thinks it's hilarious that I put so much importance on bringing the correct undergarments but when I got him his first pair of performance Give-n-Go boxer briefs, I certainly didn't hear him complaining.
Performance underwear is quick-drying, wicking (especially good for hiking and humid climates), odor-resistant, and long-lasting. You do pay for it however at around $20 a pop! Look for sales and you can get closer to $10. Totally worth it in my opinion.
Have you seen ExOfficio's ad "17 countries. 6 weeks. One pair of underwear. Okay, maybe two." Well the ad is great and so are the underwear. Unfortunately they seem to be switching to a new model which I haven't tried yet but I do highly recommend the Give-n-Go.
Uniqlo Airism Ultra - meh. They seem to check all the right boxes, until you travel with them. I seem to sweat in them more and am not sure if their odor-resistance is up to par.
There are other varieties out there. REI has their own line, UnderArmour, and other athletic brands.
Alternatives
Commando I will say that this is not something I do at home but on my most recent trip to Bali, I found myself wearing underwear less and less. Sure there's the issue of having to wash your pants more often so I mostly just went "free" with skirts. With the heat and humidity it was just wonderful.Disposable These are not anything I'll probably ever try but I wanted to add it to this list because I'm sure it has it's place somewhere out there in the travel world. They could be useful on short trips but I just find it wasteful.
Slip Shorts Thin slip shorts are fantastic under skirts to not only avoid chafing, but give you some modestly in case of a high wind peek show!
Variety
It's funny to say you want variety in your 3-4 pair of underwear, but you do. This goes for guys and gals.Quantity You could get by with 2 but I prefer 3 or 4. Okay who am I kidding - I bring 5.
Colors Bring some darker ones for more rigorous or period days and lighter colored ones to wear under light-colored clothing.
Style To each his (her) own. Although I only wear thongs at home, I like them less when traveling in the heat. I do bring some sort of thong to avoid panty lines with snug pants, a bikini or brief for under skirts, and a seamless that can go with either.
Laundry
Since you have quick-drying underwear, washing them is a breeze. Rinse them out in the sink (daily even) and you'll have fresh underwear in the morning . Wrap them in a towel and squeeze out the extra water and they'll be dry in no time. Shoot, I've put mine in the sun and had them dry in about half an hour!Panty liners
I know the idea is to pack fewer items, but almost always have a few micro panty liners along. I mainly use mine on long flights to extend the life of my undies. They are a godsend if you won't be showering for a while.Liners don't really stick to the ExOfficio Give-n-Go fabric and it seems like I'm going to harm the material. So just don't plan on wearing your Give-n-Gos on the plane with liners.
That Time of the Month
We all know that it doesn't matter if you JUST had your period the week before you're going to travel, your body gets on holiday and says "oh, I must have a period immediately!" So pack accordingly.Definitely have some dark colors and consider period panties or reusable pads (Amazon has charcoal bamboo washable sanitary pads).
I have to say that I have never tried period panties but I like the idea! The different brands and styles vary. There are some that will actually replace a tampon or pad! Less stuff to carry (you can't even buy tampons in some countries), better for the environment, and WAY better for having to find a place to dispose of used items. Since I have entered menopause (woohoo!) I will probably never try these but would love to hear from anyone who has!