Kathy, I imagine you have a few to add!
Here's my Hot Chocolate Powder:
2 c. powdered milk
3/4 c. cocoa
1 c. sugar (I use fruit sugar, aka instant dissolving or superfine)
Blend the above in a food processor to mix. This step seems to make the cocoa mix in better, otherwise it'll taste more like hot cocoa (you know that grainy cocoa taste). Mix 2 Tbsp powder with 3/4 c. hot water. For extra creamy hot chocolate, I add canned milk.