The bigger, the better and usually higher quality. You will see that after the leaves open, under hot water. Oolng teas usually have the biggest leaves - they are normally rolled into balls and also quite expensive. If you want something cheaper (under 5 euros/100 g) but still very good, try Gunpowder (also rolled) or Chun Mee. These have a strong taste characteristic to pan oxidized Chinese tea. If you don't like the strong taste, then you're either infusing it too much (infuse for two minutes or less) or should try some of the Yunnan varieties, specifically Mao Feng.

https://worldoftea.org/is-chinese-tea-safe-to-drink/

If you don't like pan oxidized Chinese tea at all, try Formosa (Taiwan), Korean or Japanese steam oxidized tea: Sencha, Bancha. Speaking of twigs, there's also a variety of Japanese twig tea which actually tastes very good - it's called Kukicha. Theese tend to have a milder taste.

https://japanesegreenteashops.com/pages/japanese-tea-types

If you're located anywhere in the EU, I used to buy from Teegschwendner before a Demmers franchise was establised in my country.