Brewing help

Hi, guys. I was wondering how much tea should I brew per 100 ml of water. I only drink black tea (earl grey) and green tea (long jing) and I was using 1 tea spoon per 150ml but then I looked up to the guides of internet and they were so much changing between guides so I decided to ask it here. Btw I dont have any balance so if you’ve any recommendations to weigh tea looses I’d like to hear it.