There are some problems with being a new designer as I have foundout the hard way. There may be designs that you think are original but in turn have been thought of by someone else. I found this out when my design ideas collection that I made about 40 different illusions that about 31 of them are thought of in some way shape or fashion. I was very sad at this. Such as productions and vanishings that look like the Zimmerman base or style. As a new illusionist you will not know this. I have been a working pro for years of that I sat down for 3 years designing and building my own illusions mostly I was upset at the work that some big name illusion builder did. And the ones that did great work were so expensive (but worth it) I wanted to have my show stand out from others and it takes a lot of time and trial and error. As I have stated before Rand Woodburys Illusion Works helped a great deal!!! But most of all you need to do your own reasearch and make sure that you are not duplicating someone else work. This takes ALOT of time but you will see that its worth it! So to all designers I tell you to keep up the notes and if you are low on funds then do what I did...do it your self you will SAVE!!! There are a lot of resources to help you bring your ideas to life and a lot of pro builders that will take it the next step for you such as Owen Redwine who is a builder/consultant who I believe is beyond business , he connects with you and what you are trying to do.
Good Luck!

As a Caviat to Lusion's post, An important part of R&D is studying whats been done. What works and what has not. Who's doing what and who is not. Understanding the needs of the market and what's missing or whats needed. There are many simple basics of magic most things have been done its up to us to present things in new and interesting ways not nessasarily re-invent the wheel. New things are ALWAYS being developed. Whats important is always and continualy pushing that envelope. Creating new and interesting effects but most importantly expanding and changing the existing one's. More than one way to skin a cat per say....
Just my thought...