I hope these basic rules list might help someone. It's quite simple and really basic, but somehow useful and easy to remember. As for me personally it's a good way to check what you're working if it's good or bad and how to improve it and make better.
----------
1. Story Telling Environments
What is your maps general story? Why is the player there? What is the purpose behind your environment? The depth of your game world will reflect how long you've spent on designing the background story.
Your environment should always be designed to tell a story without having to explain it. "Set dress" your level to have "character". Put clues into the level that if a player looks around, they could piece together a story of what happened here. Environment design should tell a story and let the player put the puzzles of the environment together. Visually show the environment's story through set design. Let the player fill in the gaps. Why is the specific prop placed there? How did it get there? How did each room became to be this way? What happened?
To help you become better level designer, become a "player" level designer. Put yourself in the environment you are creating. Think of how would the environment came to be? What is the story behind each prop placed? How did it get there?
2. Pick a Theme
Theme is a unifying idea. Theme is the consistency of your environment. It shows through story, from one map to another. What is your theme for your environment? Dark night? Romantic bright moonlight rays or creepy foggy disorientation? Rainy dark night? The choice between interior and exterior could make the difference.
3. Side Rooms
Side rooms allow for the player to experience a bit more choice and freedom in the environment, rather then following a linear approach. Let the player explore without taking them away from the main path too far. You can include items, spawn infected and create rescue closets within the side rooms.
Give the player ways to get to the same location different ways. Give them an option of going A or going B. Either choice leads to the same location, but having the freedom to choose is important.
4. Psychology of Guiding the Player
We tend to seek light and higher ground. You can guide the player subconsciously to locations in your level by using lights and having higher ground (make them go up the stairs for example). If presented a choice with going up the stairs to a lit room or going downstairs into a dark basement, majority will choose the stairs going up to the light without consciously thinking about it. Use this in your own campaign design.
6. No Way Back
Way to add tension to the level is have the player drop down to the unknown, such as a hill slope or sewers. It helps to build tension. From level designers point of view it helps with performance by closing off the area where the players have been with portals.
7. Interactive Environment
Nothing helps to add believability to the environment then having the player interact with their surroundings. But make the player's choice matter.
8. Color Palette
Color theory is very important to designing the feeling and emotion of your environment. It has a huge impact on the visual quality of your environment. One of the ways is to balance cool vs warm color palettes.
9. Attention and Contrast
Show where the player needs to go with contrast. Broken wall holes, or holes in the floor. Broken tree stumps among the forest. Use silhouettes that add contrast and grab attention of the player. Contrast of objects out of place. Contrast light vs darkness. Contrast in geometry.
10. Interesting gameplay spaces
Design interesting gameplay spaces. Spend time researching your location, setting up the story and picking a theme. Don't open the editor until you have something interesting that hasn't been done before. If it has been done, just make it your own way and better.
----------
Taken from a great site with a real lots of interesting articles
http://worldofleveldesign.com/
Search
Member List
IRC
Help
WIP: A very basic mapping tutorial
