CLIP and HOLLOW
Euw...
I suck at photoshop but I hate using the HL textures.
Anyway I can offer little in the land of tips but here is how I go about making a level and a little trick I discovered (although I'm sure valve used it too)
Note that this example shows 1 hallway but i tend to work on 3 rooms at once.
STEP 1
Firstly make basic box rooms and make the gaps for the doors and light it with point entity lights. Texture it with the base textures that the room will use.
STEP 2
Next add the brush based lights and minor details to the floor and ceiling. In this case I have made gaps for the lights and some pipes and then covered them each with a simple func_wall brush
STEP 3
Next add the major details. I have built support pillars along either side of the hallway.
The hallway was very dark after removing the point entity lights so in order to brighten it up I added upward facing lights on the base of each pillar. These are good because they light the ceiling. However if you want a dark area just leave these out.
STEP 4
Now here is the clever tip. I added some point entity lights at 3 points each in the dead centre of the hallway. There were set to a brightness "0 255 0 50" which is fully green light but set to be very dim.
When compared to the original there is very little difference but the slighly more green tint makes the lighting a little more interesting. Valve used dark blue point based light entities in the Anomalous Materials RMF included with the HL SDK.
Here is a list of what I think works and where.
Red Tints for tunnels or areas containing pipes and vents.
Green Tints for older or run down areas of a level.
Blue in labs and offices.
Purple in areas that are subject to a lot of alien activity.
Note: Tints are best used in well-lit areas otherwise they will overpower the the original lighting although using more than one in a dimly lit area can have some interesting effects.
