At home, follow the same routines and guidelines you use when preparing for your regular block of sleep. This means making your bedroom as dark and quiet as possible and avoiding caffeine, exercise and heavy, greasy food for several hours beforehand. You may also want to use eye shades and earplugs. When possible, avoid caffeine and alcohol for 3-4 hours before the nap. Caffeine is a stimulant, and it will make it harder to fall asleep.
Alcohol affects sleep quality and makes it difficult to maintain sleep.
Also, avoid exercising just before taking a nap because it stimulates your cardiovascular system, temporarily making you more alert. Because of ups and downs in your circadian rhythms, certain times are better than others for napping. During the day, the best napping window is in the afternoon, from about 1 to 5 p.m. Conversely, it may be difficult to nap between 7 and 9 p.m. because human alertness tends to rise in the evening. These recommended lengths are designed to minimize sleep inertia the temporary grogginess and disorientation people often experience when they wake up from deep sleep.