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I've traveled a lot over the last 15 years. You can ignore the following advice if you want to. I really don't care. But I will say this, I know the following to be true.
Build and maintain a standing toiletry kit. Don't pack from scratch each and every time. At its core are your day-to-day soap, toothpaste, shampoo, etc. Use small bottles not full-sized ones. Refill them as needed. Check when you get back from a trip, not when you're running late and grabbing stuff to throw in a hastily packed bag.
Take your regular shampoo, don't risk what's in the hotel room. On the road is no place for a bad hair day. On the road is no place for experimenting with a new conditioner in different water. Feel fre to sample what comes in your room but don't count on it for a week. You've been warned; this is the voice of bad experiences.
The end of the TP roll; one maybe two uses left. Pack it. Laugh will you? Obviously you don't travel a lot. Because if you did, at some point you will find yourself stuck, short a handful of squares. The same goes for the end of the toothpaste tube. Save the last few squeezes for the road and leave the empty tube in the trash to help lighten your load on the way back. Take a new toothbrush with you. It's time to rotate your one at home anyway. In fact, throw the one at home out the day you leave.
Take a mini-first aid kit with you. One or two band-aids (more if traveling with kids), a moist towelette, and perhaps a alcohol prep. Consider a safety pin instead of a neelde and thread sewing kit. (Hint: think ultralight camping as a guiding light.) I carry one of those 1 AAA battery flashlights with me.
Take plenty of whatever regular medications you need. I can attest to what a hassle it is calling your doctor or pharmacy at home to arrange meds on the road. With kids. Who haven't eaten and are jetlagged.
Least you think I deprive myself of any worldly pleasure I love to snag samples in the store and stash them in my standing toiletry kit. Sun block, lotion, vitamins, you name it. This turns any vacation into personal spa experience. Think of them as supplementing my standing toiletry kit.
Pack a small bottle opener because part of your mission involves drinking local microbrews. Or bring a corkscrew if you're wine-inclined. Most hotels don't appreciate you using various edges and corners as makeshift bottle openers. Worse yet, you run the risk of breaking the bottle. (Don't ask; not a pretty story.)
Small thing but I have a habit of unpacking my toiletry kit when I first arrive and putting it in the bathroom. From then on out, whenever I go in, I'm prepared. I don't use a hair dryer but I can't imagine the one in the room is so bad, idiosyncratic, or unworkable that you just have to bring yours along. Travel light, enjoy yourself.