Ideally, one should not get one's hair cut or do a shave during Navaratri it is said that this angers Goddess Durga and invites her wrath. If you have work commitments, then you can probably give yourself a shave a couple of times, but avoid getting your hair cut. Also do not organize a mundan ceremony for your child in this period. You can't obviously give up sleeping for nine days, but one should avoid sleeping in the afternoon during this time.
This is especially true for those who are fasting, since it is said that if you sleep during the daytime during Navaratri (at a time when you should be up and about), then all the "good karma" attained from the fast goes null and void. Avoid. And if you are fasting, then here are a few tips that will come in handy. Unless you are doing nirjal vrat (without water), keep yourself hydrated. This will also keep your hunger pangs at bay. If you have trouble having too much water at one go, other alternatives such as lemon water, coconut without and fresh juices (without preservatives) also serve the same purpose.
Since you can have more or less all kinds of sweets during a fast, people tend to go overboard. However, not only is sugar bad for your health, but refined sugar can lead to weight gain and lethargy, something that you don't want to have, especially after a fasting session! For healthier alternatives, you must have jaggery and honey make sure that they are pure and free from preservatives though.
