All good soaring pilots cultivate a near obsession with climbing as fast as possible in any situation. In large, powerful thermals this may mean forsaking gentle circling techniques in smooth, easy lift for the challenge of working a turbulent core to achieve measurably better climb rates. Flying in only the strongest lift, staying in it longer, climbing quicker and higher: one thermal at a time, these small triumphs facilitate further improvement in every area of soaring.
With increasing experience you will learn to sense, from moment to moment, which speed and bank angle are most appropriate for any given occasion. Then, where a beginner may have challenge enough simply maintaining full control in uniform circles, the more seasoned pilot might intentionally vary speeds and attitudes, perhaps more than once every circle, in reaction to the changing behavior of each individual thermal.