Recipe development is generally achieved through trial and error, experimentation, and taste testers. Chefs that create new recipes have learnt through years of experience and extensive trials, how different ingredients will interact with each other, how they taste on their own, and which combinations work best.
For others, recipe creation is a matter of altering existing recipes, or creating a new version of what they might have eaten whilst dining out.
I currently create a new recipe every month incorporating all of the above techniques, and am collating my ideas with the intention of ultimately publishing them.
My experience enables me to offer recipe testing, or even to help you to develop unique and tailored recipes for your establishment that target your local cliental.