That being said if the color trend is calling for bright neons, then use them but be selective about which ones you choose to incorporate and then offset them with a more neutral pairing. Also remember your audience and determine if the pop neon colors should be used for an entire dress, or just for some piping of a pocket. Never be afraid of color but use it wisely.
Fabric can be difficult to source and pair with the inspiration behind your collection. However while that may be all consuming, from a saleable perspective people will rarely care about that. As a designer it is your difficult duty to figure all that out behind the scenes, however, your clients will be most interested in the qualities of the fabric for their intended purpose for that garment. In other words if they want a summer dress it should be light and breathable, while a fall rain coat should be moisture repellent and warm. Always think of the wearability of a fabric, the reason for the garment, and the requirements the fabric must have. Until you are designing for a haute couture fashion house in Paris, you should not create a winter coat made of sheer silk.
Some fabrics that are in style for Spring Summer 2012 are crochet fabric, and loose knitwear. While lace and sheer materials are also extremely popular, the cotton and linen blends are also a winner with the crowds for spring. The reason this is valuable is to let you know what may carry forward for spring summer 2013. Fall 2012 had a lot of high twist wools and fabric with texture such as mohair and lambswool.