The trick is in the flame/temperature graduation and also in consideration of the type of oil you are using. As well as the item you are attempting to fry.
In my and family experience, we have found that peanut/groundnut oil has the highest breakdown temperature.
Let's say you are frying an 8 inch mackerel. Underneath the work, obviously, is the gas burner (since you cannot operate a wok over an electric stove - and if you do operate a wok over electric stove - that would be a problem).
Steps in learning to familiarise with the wok
First, you turn the flame to 1 cm in height (== low temperature). You provide sufficient oil so that you could use the frying ladle to swirl the mackerel around the trough of the wok smoothly. The crest is the highest curve of a wave and the trough is the lowest curve.
Gradually turn the flame up until you encounter resistance in swirling the fish. Then, turn it down a notch.
You let the fish sit there to cook, turning it over now and then, swirling it to ensure the oil is not burning.
Let's say you have five fish to cook and the size of your wok fits only one 8 inch fish. So you have to go thro the motion five times.
When you have finished cooking the fifth fish, you throw (well, please don't literally throw the fish and splatter hot oil all over) the 1st fish back into the wok and turn the flame up because now you are going to burn the oil a little to brown the fish. By the time you have finished browning the 5th fish, you would have ruined the oil and you would have to use fresh oil to fry any more fish.
But save the ruined oil because now you have the family secret oil to stir fry your chicken-broccoli dish. People will ask you where did you learn to have that "fragrance" in your chicken-vegetable dish.
The trick is in the swirling
The wok is designed to allow swirling of the food being cooked. It also allows turning your food without stuffs dropping off the edges. With each attempt you will soon get used to knowing the speed with which you could turn up the temperature.
When you fry a sunny-side-up, you have to ensure the least amount of oil and warm it up with a sudden blast of temperature and quickly turn it down. That takes some trial-and-error experience of when to turn the blast down. Usually no more than 30 seconds. When you throw your raw egg in, the abruptly fried egg would float on the oil. And you can push the egg with the ladle gently and a little and the egg would swirl slightly to demonstrate that it is not stuck to the wok. What I mean by "float on the oil", is a thick film of oil, a teaspoon of oil, not a cup of oil.
Frying fish and eggs are the two most effective ways to learn the purpose and make use of the curvature of the wok.
The test of your skill is frying angel fish/pomfret. Unlike mackerel, they are delicate fish. They tear easily. How are you going to make sure the fish swirls and how do you brown the fish.
Understanding the wok
Certainly, you might find that my thesis here is uncalled for because all you want is to know how to prevent oil from burning in the wok. However, you first need to understand the wok before asking that question.
You need to have a physical and mental connection with the wok as a soldier has a connection with his/her gun. And understanding that different targets of the weapon deserve different treatment.
You need to know when and how to prevent the oil from burning as well as when and how to get the oil to burn. So that by the time you rack up an intimate relationship with your wok, you will find your ex-relationship with your flat pans unsatisfying.