You have all the tools you need for studio quality rendering. Only problem is learning how to use lights and configure your renderer properly.
My method of lightning up the scene:
- Place and setup lights one by one, turn others off.
- 3 spotlights lights are usually enough; Main, filler and highlight.
- Use wide cone and very small hotspot to avoid unrealistic sharp light-to-dark backround transition.
- Light should never be coming from same or opposite direction of camera.
- Mainlight is the mainsource of light in scene, but also main source of shadows. Try to find good balance between those two so there's good contrast in your render.
- Filler light is used to brighten up the dark/shadowy side of your scene. To give some idea of correct brightness, I usually use dark gray or very dark blue color and shadows should be barely noticable.
-Last but not least I use one light above the scene to add highlight on curvy parts and to cast subtle ground shadow so objects don't look like they're floating.