Salad in a jar - I don't put any dressing in the jar. If you do make sure its no where near the lettuce. I reccomend not putting the dressing in the jar at all. Your salads will last a little over a week w/o dressing!
DIY How to Pack a Mason Jar Salad.Image and how-to from Julia Mirabella: Mason Jar Salads and More: 50 Layered Lunches to Grab and Go. For an easy infographic on how to pack a mason jar salad, check out this one out from eat within your means.