I found this very helpful information along with a recipe for a “fresh and springy walnut, radish and apple salad” on buzzfeed.com:

• The dressing goes in first. This guarantees that your salad ingredients don’t get soggy.
• Then go with a grain or a protein, or anything else big and chunky so your delicate ingredients do not get wet.
• Little things like nuts, raisins and cheeses come next. These ingredients need to stay dry until right before you eat it.
• The leafy greens go in last so when you turn the jar over and unload it all into a bowl, the greens will make the salad bed.

The secret to a perfect mason jar salad is all in the order of ingredients:)  I went straight to my fridge and then my pantry to see what I had on hand.  I  simply do not like to waste food so my salad was a variation of the above listed recipe.  In the jar went:

1. Pickled red onions I prepared for another meal along with a little ranch yogurt dressing
2. Sliced honey crisp apple (I always have apples in my kitchen)
3. Chunks of the last of an English cucumber
4. Walnut halves
5. And last some super greens (baby spinach, baby kale and red & green chard)

Instead of unloading the contents of the jar into a bowl, I just turned it over and rolled it around a few times.  This salad was so crunchy and good and the vinegar pickled onions with the yogurt dressing coated each ingredient perfectly!