[Manny]

The three things I can think of right now:

-add caulk to every surface the player can't see
-leave one tiny bit of space between an object and another object (a box and the floor forexample, the box should "float". If you use a tiny space the player can't see it)
-when two brushes meet like this:

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Create a "triangle" effect. Use the vertex tool (press v, you can also press x, it'll work too). It's hard to describe, something like this:


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Mmm...I don't have any pictures of this. Maybe you understand what I mean.