Best advice overall is to experiment.
I’ve gone primarily to what you might call “glowing” canvas toning and sketching colors. Simplest is magenta, but anything on the warm side of the wheel pleases me most, including yellow, orange, rose violet and so on. Indian yellow makes for an extremely glow-able background.
Note that my primary use is in landscapes, and they feature a panoply of greens… so the “glowing” background is also usually the complement in hue.
Any holidays (missed bits, especially along edges where hues or warm/cold contrasts abut) contribute to interest in given passages as the background flashes through. But that doesn’t work if it’s overwhelmingly patchy. At its best, It’s a kind of built-in broken color effect.
Edit: on reflection, the Indian yellow is effective because it more or less suggests flashes of sunshine…