realskiers

I always just make Gatorade 1/3 to 1/2 strength.  Of course that is partially because I'm cheap and lazy.  Pedialyte is the standard well balanced drink but as said, expensive for what you get.

If you like Green tea, you could add honey or brown sugar to get to about 50-70 cal per 12oz.  That is not too much if you are actively skiing and the sugar does help transport the water into you body.  You can add a three finger pinch of salt per 16 oz H2O if you want the sodium (which is not a bad idea if you cramp).  The best way to do this is to add the salt to the water first.  Taste it and if it isn't saltier than your tears, it's ok.  Then add tea, sweetener, cinnamon etc