OK - I've finally gotten a chance to start this tutorial on how I design a rocket with Illustrator.
First step is to decide what your nose cone is gonna look like from the side. I've chosen to create something that looks like an elliptical nose cone for a 30mm tube (Not only should a 30mm bird rock with the D5, but I also use 30mm for parachute duration contest rockets). Photo 1 shows the side view of the nose cone.
Photo 2 shows how I run the nose cone through Excel (any spreadsheet will do). The calculations are from G. Harry Stine's Handbook of Model Rocketry for transitions. Note that a cone shape is simply a transition with a smaller diameter of 0.
(note - the pics may be out of sequence - this is the fault of the forum software)