Do not drink or eat caffeine after 3:00 p.m. This includes coffee, tea, cola drinks, and chocolate.
Do not smoke or use other tobacco products. Nicotine can disrupt sleep and reduce total sleep time. Smokers report more daytime sleepiness and minor accidents than do nonsmokers, especially in younger age groups.
Do not drink alcohol. It may make you sleepy but also will probably wake you up after a short time.