Who wants to cut up carrot sticks when you're feeling peckish? Or trim radishes? These are not difficult things to do, but when I'm hungry, I want something to eat immediately. So I've taken to making sure there's always a small supply of cut carrots (peeling the carrots when I'm not hungry) in the refrigerator drawer, and I wash, trim, and store the radishes as soon as I buy them.
We enjoy cut-up beets in salad, but baking a beet takes up to two hours. So I've added beet-baking to my post-grocery run routine. The peeled baked beet goes into the fridge, ready to be cut up and eaten.
One of my favorite nibbles is a simple marinated cucumber-dill salad from the Second Avenue Deli Cookbook. Overnight marination is recommended before consumption, which is a deterrent if you want your cucumber salad right away. But I am starting to just make it routinely--again, shortly after I get back with the groceries--so it's always waiting in the fridge.
These simple prep tasks make for healthier snacking and foster a little more variety in the diet.