There are locations that are known for a daily shower or summer storms. Pack accordingly so that the rain does not ruin your trip and create unnecessary hubbub trying to figure out plan B everyday. Consider packing plastic ponchos (they take up virtually no space so pack a few of them), an umbrella, and lightweight rain jacket with a hood. They make rain shoes as well that feel like tennis or hiking shoes and are quite comfortable – I bought a pair when taking a vacation to Niagara Falls because you walk through quite a bit of water and it can easily rain. Consider packing a waterproof disposable camera too as you may get some good pictures, even in the rain.
The airlines work very hard to ensure that your checked luggage arrives with you. However, mistakes happen. If you’re planning for a significant trip with your loved one, consider packing half of your belongings in your bag and the other half in your partner’s bag. Your loved one can do the same. Should one bag be “lost”, you will both have clothes at your destination. Using color coded Packing Cubes can make this process very easy!