It you aren't getting enough rest because of your stiff, flat, squashed pillow, you should take the time to break in the pillow to soften it up. Not only will breaking in a pillow make it a softer cushion for a good night's sleep, it will help remove the natural allergens that build up from regular use. Smacking around a new pillow to break it in will help as a stress reliever for the sleep you may have lost as well.
Shake, hit and fluff the pillow after you sleep on it every morning. Moving the pillow causes the stuffing contents to spread out and get lighter, a concept known as loft.
Apply a light sprinkling of fabric softener onto the pillow and place it in a dryer. Tumble the pillow on the air-only setting for about 10 minutes. Tumbling the pillow while the drier is set to a heated setting may burn the pillow's stuffing.
Place the pillow outside on a clear day so it can air out. Leaving the pillow outside in a clean area will dry any absorbed humidity and whisk away stale scents while replacing it with a fresh outdoorsy smell.