Summarize:

Don't settle for just a plain cardboard box. Find a cute box to store your items to give your care package a personal touch. You could, for example, find a box in your partner's favorite color. You could also decorate your own box. If you want to do something really cute, draw hearts on on the surface of your chosen box. In each heart, write something you love about your partner. In addition to decorating the outside of the box, decorate the inside. You could glue strips of attractive fabric along the inside of the box. You could make a photo collage on the bottom of the box. You could also draw on it, decorate it with stickers, or use stencils. Store heavier items on the bottom, so they don't crush smaller, more delicate items. Anything breakable should be wrapped in bubble wrap or something similar. You do not want anything to break on the journey. If you're sending foods or drinks, make sure the packages are sealed carefully. You don't want anything to leak. You may want to put liquid items in plastic bags just in case they break while shipping. This way, any spills will be contained. Once your package is decorated and packed, you can send it in the mail. Stop by your local post office to purchase proper stamps. Check for an estimate of when the package will arrive. If you need it there by a certain date, you may have to pay for faster shipping. It's a good idea to get a tracking number. This way, you can track the package's process online and give your partner an idea of when to look for it.
Find an attractive box. Decorate the interior of the box. Store your items carefully. Mail the package.