We present here some of our modeling efforts for gas discharge plasmas, used in a number of applications in materials science. Different kinds of modeling approaches are applied, including fluid models, particle-in-cell - Monte Carlo (PIC-MC) models and hybrid Monte Carlo - fluid models, for the plasma behavior, as well as molecular dynamics simulations for thin film growth. The application fields include the deposition of amorphous hydrogenated carbon layers (diamond-like carbon) from hydrocarbon plasmas, the dust formation in silane discharges, the surface treatment with dielectric-barrier discharges, magnetron discharges used for sputter-deposition, dual-frequency capacitively coupled radiofrequency (cc-rf) discharges in CF4/ArN2, for etching applications, and glow discharges for spectrochemical analysis of materials.