So I made a bad choice at lunch, maybe had too many calories? Tough luck, kid, but don't think it has "ruined" your day. Take a walk or do some jumping jacks and make a better choice the next meal. You can't punish yourself forever. Accept it and do better next time.
Get a pedometer and get walking! Try to get that minimum 10,000 steps per day, and you will find yourself wondering what extra walking around you can do to make it to your daily goal.
If you buy the pre-washed lettuce mixes in the bag, take it out of the bag and store it in a plastic container with a lid - it will stay fresh for longer. I guess it keeps more moisture out.
For air-popped popcorn, instead of salt and tons of butter, I use Mrs. Dash Table Blend and a table spoon or so of heart healthy spread, melted. Put the popcorn in a storage bag, shake in some Mrs. Dash and the "butter" and shake it until it's all blended. Yummy and still healthy!