Easy clouds

Martin Nebelong - How to create easy clouds

Realistic Lighting (Interiors and Exteriors)

SlackerStudios: Realistic lighting set ups

Randomised weather

Drinkwater200: Randomised weather patterns

How to make stars and The Moon

Real time build of a night sky

How to create beautiful skies

Make your skies more realistic

Logic Gadgets: Sun & Sky

Sun & Sky description

How to adjust view distance (fog) and motion blur

How to change background fog and motion blur from the default

How to make a starry sky

Make some stars