Step 1: Check the weather
This may seem obvious, but every once in a while you end up going somewhere where the weather is completely different from here and then you end up not bringing anything for the occasional cold weather day or obscenely hot day and then you’ll curse yourself. Because if you’d just taken 5 seconds to check your weather app you would have realized that sometimes it rains in LA and that you should have brought something besides flip flops. Also bring an umbrella. If you don’t it will definitely rain and then you’ll be wet and sad.
Step 2: Build from the bottom up
When you start packing pick out 2 pairs of shoes for everyday wear. They should be comfy, easy to walk in, and preferably cute. Everything else you bring has to go with at least one of those two pairs of shoes. If this seems impossible reexamine your shoe selection and then your wardrobe. Once you pick your clothes make sure every top goes with at least one bottom and every bottom goes with at least half your tops. This is important because you’ll be able to re-wear things and still avoid repeating outfits. Also your bag should go with your clothes, you really only need one, so make sure it goes with both pairs of shoes.
Step 3: Plan for the unexpected
Now don’t go crazy and bring you parka to Hawaii, but remember half the fun of travel is making plans at the last minute. For example, this summer in Budapest I bought tickets for an opera the same night. Fortunately, my parents raised me correctly and taught me that the only people who wear jeans to the opera are people who have no appreciation for the artistry and effort that goes into it, and therefore have no business being there. Had I not planned for this it would have seemed as though I didn’t give a crap about the hard work that went into the opera I couldn’t even understand. Fortunately, I had a dress with me and managed to look like my attendance was not some last minute US tourist decision.
Step 4: Don’t forget the necessities
You need at least 10 pairs of underwear. There are websites that say you only need three but there’s no way in hell I’m doing laundry every three days. What if I go swimming, or get my period? I’m going to want to change my underwear and then there’s only one day between necessary underwear washings. Also bring woolite to wash your clothes in the sink just in case. Do you want to be wearing used underwear and smelly clothes on day 15 of your trip? I didn’t think so.