I’m always dehydrated. It’s no good. I fainted whenever I would go skiing from the combination of dehydration and altitude. I was probably the only kid who was reprimanded regularly for being under-hydrated. So these days I look for ways to remind myself to drink more water (and juice and whatever). Reusable water bottles are great, but only if you remember to fill them. I think if I had the Pickle Brine Water Bottle ($12) I would take it with me everywhere!
Also, pickle brine is actually a somewhat recommended hangover cure. Water and salt are useful to kick-start your recovery.
Source: Archie McPhee & Co.