Trends in Slater's constant

I am aware of the various Slater rules to calculate the effective nuclear charge, $Z\_\mathrm{eff}$


However, how can I decide the order in which the orbitals 2s, 3s, 3d, 3p, 4d, and 4f stand when compared regarding the effective nuclear charge on them?


Is calculating the $Z\_\mathrm{eff}$ on their individual electrons the efficient way or can some trend or method be established ?


