Step 6: Look Around You
Take a look at the images attached to this step. I've collected some cool images, and made a quick N-level-coloured overlay in Photoshop to illustrate how you might be able to see shapes, patterns and ideas for levels in the things around you.
For us at Metanet, one of the most inspiring sources for N levels has always been architecture. We walk around cities snapping pics of interesting buildings and parts of buildings, and then work the shapes into N levels. You could also check out the Architecture section of your favourite bookstore. Look up Tadao Ando -- his work was one of the first inspirations for N's style.