Ah, holidays — those blessed days where you're free to kick back, relax, and put your worries on pause. Of course, your beach getaway or city adventure is, more often than not, preceded by travel, during which you may fail to keep a normal sleep schedule , grapple with plane-inspired anxieties , or stress over breaking out of your routine for a week. No crystal will solve all of these pre-holiday woes, but there are a few varieties that may very well offer some comfort should you toss them in your carry-on before heading for the airport.