When a project's development team gets into production mode everyone wants to jump in and start working. However there is a definite order to the process to avoid chaos and many ways that teams could end up "putting the cart in front of the horse."
Myself as a level designer there are some things I need before I can do my job and some things that get in my way if done too early. Here is the process I enjoy working with.
1. I need the expectations for the level.
2. What is the environment going to be?
3. Are there missions or story points that need to be conveyed?
4. What abilities will the player have at this point?
5. What enemies or challenges are expected to be present?
5. What is the expected difficulty?
This helps paint a much clearer picture of the level and what I need to design. Next I feel it's important to have the artist do some concepts of the environment. What is this place going to look like? Do the directors agree? Is everyone happy with this look? These concepts help establish a mood for the level as well as keep all the level designers in sync as to what the agreed upon look is.
Gather reference material. Layouts are more believable if they reflect real life. So find reference not to copy but also to help keep you grounded and inspire you.
Next I like to do a "paper layout." This of course doesn't need to be on paper, it can be in Sketch Up, Photoshop, Illustrator, or whatever you're comfortable and fast as using. Once it's made get some eyes on it and see if everyone is onboard. Keep in mind the information gathered combined with the concept art.
Then if time allows I like to build a very rough scale test in the editor to get an idea of the size of the space. This is especially helpful when making city or urban areas. This helps establish building sizes and the play space distances. This can of course be done during the block out phase but it's nice if you have the time.
Next of course is the block out where we create the basic shapes and layout of the paper plan. I don't want to get into the details of how you create a successful block out, that's not what I'm going for in this article. But remember to create your sight lines, cover and other elements essential for game play.
Once the level designer has created the block out it's time to add some enemies and get "fun" happening. Is the game play fun? Is the cover working? Is the space interesting to play in? Get lots of eyes on the level. Have lots of people play. IF everyone is happy move on to the next step.
Once the block out is approved and fun the artists can replace the block out pieces with models and add the details to make the environment look like a real location in the game's world.