The key to a good bike ride, whether it be for a daily commute or a fun, recreational ride is being prepared. In order to ensure that preparedness, I always make sure to set out my riding gear and daily equipment before I go to bed at night. Some things go in my pannier, other things in my backpack. I use a checklist to make sure I don't forget anything...
There is overlap in these lists as the equipment I need varies depending on my activities for the day. For example, on Fridays I teach a class in a home daycare so in addition to my regular commuting items I also need to bring along a picture book, art supplies, a Humpty-Dumpty stuffed toy and a large red scarf with blue flowers on it.
In addition to my checklists, I always check the weather the night before to see what kind of outerwear I will need.
Here are my lists - what's in yours?
Commuting List: an extra layer of clothes, hat, neck warmer, gloves, reading glasses, sun glasses, wallet, cell, high visibility vest or jacket, lights, memo pad, pen, coffee mug, pump, snow goggles
Fun Ride: snack, map, pump, glasses, high visibility vest, extra layer, full water bottle, cell, memo pad, pen, wallet, lights, snack
For the Gym: toiletries bag, swimming suit or gym shorts, bathing cap, top off skin lotion, towel, change of clothing, gym shoes, snack
If you have a choice between riding and driving, putting everything out the night before may tip the balance in favor of riding.