Talk in a quiet voice, but do not whisper. Watch for neck stain. Use good posture, a relaxed jaw, and a wet and open throat. Use diaphragmatic breathing when singing and when speaking to support the voice and decrease vocal strain. Aerobic exercise can be of benefit in promoting better breath stream management and overall vocal health.
Relaxation exercises can be of benefit.
Even yawning before singing helps to relax the muscles associated with voice use. If you do a lot of talking throughout the day, then set aside some time for quiet activities. Zinc Lozenges Avoid dairy products as they are mucous producing. Limit the use of decongestants because they are drying. Warm-up the voice a little before trying to reach those low and high range extensions.