I learned a great tip the other day; I tried it this afternoon and have decided to share the success.
Is anyone else annoyed when avocados quickly turn an unsightly brown color!? Fret no more. If you have half of an avocado left over (rare, but possible. :)) keep the seed in and put in plastic, removing all the air around the avocado, then refrigerate. I couldn't believe it when it worked! Supposedly, if you have leftover guacamole (again, rare, but possible) or if you've made it for a party and you don't want it to turn brown before serving, you can do the same thing-- put the seed in the bowl, cover, and refrigerate. I haven't tried that, so I won't vouch for it. But that's my tip.
My dinner tonight was a salad of fresh lettuce, avocado, grape tomatoes, feta cheese, with olive oil and balsamic vinegar. Mm, mm!