Any craftsman will practice his skills, working on them over and over. Any photographer worth their salt will practice not only taking photos, but working with their equipment as well. I have seen on many blogs posts talking about swapping lenses quickly, but they always say practice in favorable conditions in good light. Lets take practicing lens swapping a bit further.
I was out yesterday walking through the snow, getting used to my new Black Rapid Double Strap, keeping sharp with handling gear in windy cold conditions, and just enjoying the scenery when I decided to swap from my wide angle to a telephoto. Problem was I couldnt set my bag down because I was in the middle of a field in deep snow. Here's the challenge: swap out your lens with out setting down any gear, then try to do it with gloves on. Try it in the dark with minmal light. Could you do it by feel alone? Whats it like handling your lenses and caps with your gloves on? Practice working in adverse conditions before you find yourself in them not knowing what to do.
Remember to keep practicing not only taking and composing photos, but working with your gear. The better you know it the faster you will be in the field when it counts.