You are at the food store and there is a huge bin of melons. How do you know which to choose to get the best value for your money? In general look at the dimple where it attached to the rest of the plant. There should be a clean, dish-shaped scar from harvesting. If it is displayed at room temperature (not refrigerated) it should have a pleasant aroma.
First check the entire melon for any bruises, soft spots or cracking. Go for the fruit that is dull; a shiny surface means it is not quite ripe. Choose a melon that feels heavy for its size.
Looking at a watermelon, you may discount the ones with a yellow color on one side. Actually, it is the opposite. The part of the melon that is in contact with the ground will turn yellow when ripe and the surface will be slightly rough, sometimes referred to as sugar bumps. Tap the melon and listen for a hollow sound.
Honeydew melons should be softish on the end opposite where the vine was and they should be a light or yellow color but this can vary depending on the variety. Stay away from the green ones.
Cantaloupe and muskmelons should be orange or gold but not green or white. Gently touch the end where the vine was attached and see if smells fresh and sweet.
Now that you have your pick, here are some things you can do with it:
Watermelon, Rosemary, and Feta Salad
4 cups of chopped watermelon, chilled
2 ounces feta cheese (ideally goat feta), crumbled
1 teaspoon finely chopped rosemary (fresh or dried)
Salt and pepper
Toss all ingredients together, adding salt and pepper to taste. Drizzle a tiny stream of olive oil over everything and toss. Chill until serving.
[Copied from https://www.thekitchn.com/recipe-watermelon-rosemary-and-65625]
Cantaloupe and Cucumber Salad
1/2 cup olive oil
1/4 cup Champagne vinegar or white wine vinegar
1 teaspoon ground coriander
Salt and pepper to taste
1/8 teaspoon ground cardamom
1/2 large cantaloupe, rind and seeds removed, flesh cut into 1-inch pieces
1 large English cucumber, sliced on a diagonal 1/2 inch thick
2 Fresno chiles, thinly sliced
1/2 cup unsalted, roasted pumpkin seeds (pepitas)
1/4 cup chopped cilantro
1/4 cup chopped mint
Whisk oil, vinegar, coriander, salt, pepper, and cardamom in a large bowl. Add cantaloupe, cucumber, and chiles and toss to coat in dressing. Let sit, uncovered, 15 minutes. To serve, add pumpkin seeds, cilantro, and mint to salad and toss gently to combine.