I'd say it depends on the clouds. I actually think some clouds are often better than no clouds. Especially if they're moving, you can wait for a pattern to complement your composition. Even at 'golden hours' a cloud pattern can add interest and sometimes striking colors. Low, dark clouds give a moody feel.

OTOH, with a high, solid overcast, it's hard to do much with that. A CPL is useless - overcast is a giant diffusion filter, there's no directional light to be polarized. A grad ND will let you show some cloud detail vs. blown out white, but that detail is usually uninteresting. A grad tobacco filter, etc., can color the clouds, but IMO it's not that helpful. Often, the best you can do is a composition that minimizes the amount of sky in the shot.