Begin the day with stretching and breathing exercises. Whether you are practicing indoors or helping shovel snow, your body should be ready for physical activity.
Practice in front of a mirror. One of the things I wish we had at the Southington and Cheshire classes is a nice big mirror. Seeing yourself as you train is a great way to check your techniques, stances, etc.
Some kata take up more space than others. The Naihanchi kata for example take up far less space than other kata in our system since they have been flattened. That's three kata in our system that can be practiced in a narrow hallway (or in a freshly shoveled sidewalk).
Eat healthy! Your eating choices should reflect your daily activities. Osensei's wife used to cook meals specifically to balance out a martial artist after a day of training with the Grandmaster. We should all strive to maintain that same balance.