Hi there,
I always mix mine!!!!
I find them a bit strong so I open 2 sachets at a time. I put 2 tea spoons of vanilla in a bowl and the rest of the packet in a tub. Then I put 2 tea spoons of either choc or strawberry in the tub and the rest in the bowl. It may not be totally 1/2 and 1/2 but I know that I have a full sachet in each. I use the bowl to make a meal and put the lid on the tub and use that next time.
I used to enjoy all flavours but I really went off vanilla and found the other 2 too strong. This works great for me.
x x x