  A unified approach is presented for investigating coupled spin-orbital
fluctuations within a realistic three-orbital model for strongly spin-orbit
coupled systems with electron fillings $n=3,4,5$ in the $t_{2g}$ sector of
$d_{yz},d_{xz},d_{xy}$ orbitals. A generalized fluctuation propagator is
constructed which is consistent with the generalized self-consistent
Hartree-Fock approximation where all Coulomb interaction contributions
involving orbital diagonal and off-diagonal spin and charge condensates are
included. Besides the low-energy magnon, intermediate-energy orbiton and
spin-orbiton, and high-energy spin-orbit exciton modes, the generalized
spectral function also shows other high-energy excitations such as the Hund's
coupling induced gapped magnon modes. We relate the characteristic features of
the coupled spin-orbital excitations to the complex magnetic behavior resulting
from the interplay between electronic bands, spin-orbit coupling, Coulomb
interactions, and structural distortion effects, as realized in the compounds
$\rm NaOsO_3$, $\rm Ca_2RuO_4$, and $\rm Sr_2IrO_4$.
