Did you sleep well last night? If no, probably the activities you perform right before bedtime are sabotaging your sleep time.1. Don't: take the wrong pill A stuffy nose keeps sleep at bay, but so does pseudoephedrine, the main ingredient in many OTC decongestants (it has been known to cause insomnia). Do: Breathe easy with a decongestant formulated specifically for nighttime use. These usually contain antihistamines, which have been known to make people drowsy.2. Don't: use your computer right before you sleep Researchers have found that before-bed exposure to the blue light from computers, tablets and smart phones suppresses melatonin levels, which can throw off your body clock as well as increase your risk of obesity. Do: Log off at least one hour before bed, and set your alarm an hour earlier in the morning to catch up on work. You could also try dimming your screen as much as possible.3. Don't: take a hot bath It is true that a warm soak can help you fall asleep, but not if you are climbing out of the water immediately before climbing into bed. Here is why: Your body temperature dips at night, starting at around two hours before sleep. A hot bath causes your temperature to rise and then cool down afterward, which will help you relax. It is this drop in body temperature that knocks you out and the steeper the drop, the deeper you will sleep. Do: Pay attention to timing, which is the key. Bathe too close to bed and your temperature will stay elevated, keeping you on high alert. Make sure you are toweling off at least an hour before turning in.4. Don't: Overeat Research has found that going to bed with an uncomfortably full stomach can stimulate brain waves, which can result in nightmares—and the unhealthier the food, the more disturbing the dreams. Do: Thwart unpleasant dreams--and unwanted pounds--by following the classic dieter's advice to chew small bites least 15 times before swallowing.5. Don't: decide to get something off your chest Hold off until tomorrow topics that are eating you up, probably the comment your sister passed during the day or what your colleague told your boss. Talking about it is probably going to rile you up, and your churning mind will continue to keep you awake into the wee hours. Stress and overstimulation before bed are said to be the main causes of delayed sleeplessness, or "parasomnia." Do: Declare the hour before bed to be your peaceful period, and avoid conversations that will rattle you.