Start running your bath or shower ahead of time so that you don't touch cold water. Make sure your hose doesn't leak. Use insulated cup holders for cold beverages, and use straws. Don't hang out wet clothes or shovel snow. Avoid substances that make you vulnerable to chills.
Smoking is a risk factor, since nicotine constricts blood vessels.
If you smoke, quit. Avoid second-hand smoke. Caffeine is also a vasoconstrictor, and is found in many hidden sources, such as chocolate, some aspirin preparations, teas, and medications. Some migraine headache and heart and blood medications may also cause Raynaud's symptoms. Take good care of your skin.