There are usually 2 ways of deep frying in Chinese cooking:

Deep frying the ingredients directly
Deep frying the ingredients with batter.
The latter is the most commonly used method. Here are some pointer in how to deep fry Chinese food most effectively.

The sizes of the ingredient pieces should be uniform.
The dimensions, including the thickness of the pieces that you are frying should be as close as you can get them. Otherwise, some pieces will be overcooked, some will be undercooked, and even the colors will be different piece by piece.

Marinade the ingredients in the batter/paste
This will enhance the taste and the aroma of your cooking.

Maintain adequate oil temperature
The oil temperature require for each dish will vary depending on the ingredient types, sizes, batters, wraps, etc. For those not easily cooked through, they will require cooking twice (see below). For those easily cooked through, it can be done simply in high heat.

When deep frying, maintaining constant oil temperature is a must. Most idealy, the ingredients need to be put in together. If you are cooking large servings, then divide them up, but still put each divided servings in together to get the same taste and color. Once done, pick them up with a strainer to preserve the appearance.

Some dishes like the ones that require chicken or fish rolled into balls are not easily cooked through when deep frying. So these will require deep frying them twice. The first time using medium heat until 70, 80% cooked. Take them out, crank up the heat to high, then deep fry them again to achieve the desired results.