Steam Community :: Guide :: p0rtalmaster's Hammer Guide Series Part 02/19
How to optimize a map in Hammer Editor - Quora
Steam Community :: Guide :: Hammer Aesthetics tutuorial for portal 2 maps
How to optimize a map in Hammer Editor - Quora
Why is there a hint brush here? I'm trying to learn from official maps. And also what would happen if you only used area portals instead of hint brushes and vice versa? :
Valve Hammer Editor - Valve Developer Community
How to optimize a map in Hammer Editor - Quora
A Guide to Lighting in Source – Part Two – LambdaGeneration