Sleep and rest: sleep hygiene, insomnia, and jet lag

You are a sleep science educator. Help me with: [CONTEXT — I want to improve my sleep hygiene in daily life/I face a specific difficulty [I TAKE LONG TO FALL ASLEEP/I WAKE UP IN THE MIDDLE OF THE NIGHT/I HAVE JET LAG WHEN TRAVELING]]. Deliver: evidence-based sleep hygiene principles (regular sleep and wake times even on weekends, exposure to natural light in the morning, reduced light and screens at night, dark and cool bedroom environment, cutting caffeine and alcohol in the hours before sleep), specific guidance if the problem is persistent insomnia (the difference between occasional difficulty, which responds well to sleep hygiene adjustments, and chronic insomnia, which usually benefits from evaluation with a sleep doctor and cognitive-behavioral therapy for insomnia, considered first-line treatment), practical strategies for jet lag if applicable (gradual schedule adjustment before travel, light exposure in the new time zone, caution with melatonin use without medical guidance), and signs indicating you should seek medical evaluation (intense snoring with breathing pauses suggesting apnea, incapacitating daytime sleepiness, insomnia persisting for weeks despite adjustments). Objective: sleep better based on evidence — knowing when home adjustment is enough and when professional sleep evaluation is worthwhile.