I've been traveling around the world for 2 years with just a carry-on - here are 12 items I can't live without

An absolute must when traveling, especially if you'll be using many different showers — whether they're at hostels, gyms, or Airbnbs — is to have some good shower shoes. I've known too many people who pick up ailments such as athlete's foot because they had no shower shoes on. Or your rental apartment floors may not be the cleanest, so better safe than sorry.

The shoes don't have to necessarily be ones you'd wear out and about, but they should be durable enough to get wet on a daily basis. I've found that these Ipanema Wave Heart flip-flops get the job done well and are cute to wear both indoors and out.

If you're as clumsy as I am, a Tide pen will save you — and your clothes — every time. Formally, it's known as Tide To Go Instant Stain Remover, and nothing works quite like it. Best yet, it fits in your pocket or your purse.

You never know when you'll need a flashlight, whether it's to find your way back to your Airbnb or to use it while unlocking your door. This Pocket Credit Card LED flashlight is ideal; it's small yet efficient, and can fit in your wallet.

Without a travel adapter, I wouldn't get very far. When I found this one, designed by Travel Fashion Girl, I knew I had to try it out. I love the Best International Travel Adapter, and recommend you try, it, too.

It apparently works in more than 150 countries and its bright red color doesn't easily blend in with the white walls you'll often encounter during your journey. It has two USB ports, and I also love that I can charge three devices at once.

When you think of Ziploc bags, you may think of the items you put homemade sandwiches into. But a friend introduced me to Ziploc Big Bags, which hold three gallons each and are my version of packing cubes.

Not only do they make you a more organized packer, since you can color-code what you're packing and see everything through the see-through bags, but you can then squeeze out the excess air once you're about to seal them shut. Plus, you can save a couple empty ones for dirty clothes.

Added bonus: Bed bugs are sometimes an inherent part of traveling and they hate plastic, so if you have all your items sealed in these Ziploc bags, it's yet another bed bug precaution you can take.

For smaller items, I also use Ziploc's gallon-sized freezer bags, quart-sized freezer bags, and sandwich bags. They also make great portable laundry machines — just put in a clothing item, some liquid soap or shampoo, and water, then close and shake it up, and voilÀ!

I bring extras of all four types of bags, plus a couple of garbage bags (in case there's no bathtub or shower to store your bags in, a preventative bed-bug measure), as you never know when you'll need them.

When I'm traveling, I live in my Palladium baggy canvas boots — they're perfect for dressing up or down, to wear with a skirt or on a hike. I bought them randomly at a mall in Warsaw, Poland, when another pair of shoes wasn't working out for the long haul, and haven't regretted it since.

They've made it through everything from hiking the Blue Mountains in Australia to walking endless miles down Croatian cobblestone streets. Usually, I wear them laced up so they look more like boots than shoes, but I love how versatile they are if you don't want to go for the boot look.

This 10-liter ultra-compact backpack folds up so much, it fits into the palm of my hand. I keep it in my day pack or pants pocket and have used it all over the world. Plus, it weighs next to nothing, which is also a big perk.

If you've ever wished duct tape would come in a travel-friendly size, your wish has come true with RediTape travel-size duct tape.

On the road, I use it way more than I'd ever anticipated: from using it to patch up my purse to affixing it to my travel bag's zippers to prevent bed bugs from crawling inside (a personal theory). RediTape's slogan is "Don't get stuck without it" — and I couldn't agree more. You never know.

One of the best inventions ever is the sleeping bag liner. Especially the silk variety, like this liner from Treksilk, which is less bulky than ones made from other materials.

Whether you're cold and could use another layer of bedding at night or the sheets and blankets are questionable where you're staying, it comes in handy time and time again.

Lavender essential oil is not only calming as aromatherapy and can work as a sleep aid — try a few drops under your nose or on your eye mask — but it's also good for dry skin. Lavender oil allegedly deters bed bugs, too, so I tend to sprinkle and spray it onto my luggage, just in case. I like this Plant Therapy lavender essential oil that I received as a gift and now keep gifting others.

How many times have you wanted coffee, but for whatever reason, you can't get it? Maybe the Starbucks line is too long at the airport, or the flight attendants haven't started serving beverages yet.

Well, problem solved if you bring along some instant coffee, like Café Bustelo Instant Espresso Sticks.

Just put a packet in your water bottle, shake it up, and presto — you have coffee! You'll avoid a caffeine headache, as well as one from long coffee lines.