Before today I didn't know the difference between RSA padding for encryption and for signing, I think this answer describes it pretty succinctly, however, I don't know if there is an optimal padding to use or if there are any deficiencies in current paddings I should be wary of (for example, PKCS for RSA encryption).
I came across RSA-FDH and RSASSA-PSS, but don't know if there are any other paddings available for RSA signing or if the ones I mentioned have any known weaknesses/deficiencies.