Water
Ironically, water is both a giver and a taker when it comes to sleep quality. Failure to hydrate properly over the work day will see you toss and turn as your body searches for much-needed nutrients, and drinking too much before bed will bring on the call of nature multiple times over the night. The best recommendation is to get your two litres in before dinner, and avoid gulping down too much water in the last two hours before bed.