Thromarcadia

Remember, also, all those space objects in the Scene Browser which you can combine with and into your imaging. scene.  Also, flare and all those other light effects which you can add/size to say bulb lights in the effects panel

See the all Carrara image attached--very quick and simple demo try..

Also, don't forget to make use of billboards(Splats) to which you can add different density/sizes of star areas to different parts of your scene.

Brian
Some great free Photoshop tutes which are very simple to get you started also.

bwtr