Tonal correction modes
There are three Tonal Correction modules in Clip Studio Paint: Hue/Saturation/Luminosity (H/S/L), Level Corrections, and Brightness/Contrast. H/S/L is useful for adjusting the hues of each colour block as you paint, to make the palette more cohesive. Levels is useful for adjusting the intensity levels of the shadows, mid-tones and highlights. Brightness/Contrast is great for ramping up the colour punch where needed.
You can manually create shortcuts for Levels and Brightness/Contrast by going to File>Shortcut Settings. Hue/Saturation/Luminosity can be accessed by pressing Ctrl+U.