Milk Tea is impossible!? Kettle or Boiling water for milk tea?

What's the best method for making great tasting milk tea?!

I'm on the journey and it's so difficult to make something like the shops from Taiwan. I've even went as far as paying one of these workers 300$ for tips and recipes lol....

Biggest things I've learned that seem so basic but are hard to get it right.

Tea, Non dairy powered creamer, Sweetener, Sometimes mousse, Boba,

For me I think the hardest thing is getting the right tea taste. Is it the brand I'm using? or the ratio of tea and water? The temperature of the water?

Can anyone just give me the amount in grams of tea to water? Is it better to boil the tea or use a kettle?!