Hydrate. Keep your sodium/potassium levels up (beef or chicken bouillon, Morton's lite salt). And I have no problem popping a couple Excedrin Migraines as needed until the ickiness passes...the combo of ingredients (one being caffeine) helps me.

The one good thing I've found is the longer you eat this way, when and if you DO drop out of ketosis for whatever reason, getting back on board is far less painful than the first couple of times. :-)

I like an epsom salt bath a couple times of day when I'm going through it. It definitely helps.