Compiled from Origins of Chinese Tea and Wine
There are four factors involved in choosing tea:
Check if the shape, size and colour of the tea leaves are uniform. Look out for undesirable particles such as tea dust and stalks.
Feel the tea leaves. Estimate the weight and size of the leaves and buds. The heavier the tea leaves, the better the quality.
Take in the aroma. The tea leaves should not smell like grass or other impurities. When the tea is ready to be consumed, it should have a fresh, rich and lasting fragrance.
Sample the tea. Good tea is rich, fresh and has a lingering sweet taste. Tea that is thin and astringent is of a lower grade.