Quick tip - OPen Render Global Window by choosing Window>Rendering Editors>Render Globals. Change Presets in the Resolution tab to 640x480 for a larger render. Under Anti-aliasing quality, change Presets to Production Quality. If you're using raytracing, you should turn it on as well. Go to the Raytracing Quality tab and click the Raytracing box. Those are the main things that will help your render come out better.