Warm hands have better blood flow. Wash with warm water or some other strategy to warm up first.
For some reason, the pinky often gives more blood.
Drinking water shouldn’t effect anything.
Check your lancet. Does it have a depth gauge? You might need deeper sticks if you have thick skin.
I seem to recall that rhythmic squeezing is better than massaging the finger which somehow effects accuracy.
I actually have 3 different meters, don’t ask. My favorite is my accu-check guide because it requires the least amount of blood. I think it would be great for children since it requires barely a drop. My Keto-mojo requires a ton and my FreeStyle is in the middle. They all test about the same, accuracy wise. Next meter, look for accuracy, but then ask the forum about how much blood is needed.
I also love my accu-check Fast Clix lancet. It has 11 depth settings, a thin lance, the lancets are in a barrel that rotates, and I can easily use it with either hand. I hate to admit it, but I probably use the same lancet for about a month before switching to the next one in the barrel. Much less garbage and cheaper. Just alcohol before using and then swipe the barrel.