Hiya!
For my hot drinks, I heat up a cup of water in the microwave to very hot but not boiling - in my microwave which is pretty large, that's 1:30.
Then I take it out, pour 1/2 in the mug, add the mix, and whisk with a collapsable small whisk I have that looks like a metal spiral at the end.
This lets me squish out any clumps that get stuck in the whisk
Then I add in the rest of the water, mix a bit more, let cool about 30 seconds and foam up... and...
ENJOY!
p.s. Chunk alert! I once made the mistake of using the hot water tap from the office water cooler to mix up my oatmeal and nuked it - UGH!!! I forced it down because it was my breakfast but the texture! Hurl-ness!