I think the best way to avoid exposure is to make tricks absolutely hard to replicate.
I disagree as to method. Most exposure comes from people who purchase the effect. They aren't afraid to expose it even though they can't perform it. The more popular the effect, the more likely someone will buy it and expose it. So find something that isn't well known -- maybe like something hidden in a book. (that is where the real secrets are). Further, I think that a creative but simple method beats out a difficult method every time.
Additionally, I think that the spectator's desire to solve the "puzzle" of how you do it by searching the internet results from presenting magic as a puzzle or merely focusing on what you are doing. Our job is to entertain, not to puzzle.
However, as to presentaton, I tend to agree. My performance pieces require a lot of effort which I don't think other performers would bother to immitate. My props are a combination of regular items (empty gin bottles, apple picking baskets, stainless steel ice buckets, blue amethyst worry stones, quality stationary), home made props (dollar bill confetti, various fakes and gaffed cards) and custom, high quality props (linking rings, egg bag, cups & balls, devil's handkerchief, etc.) that are only available directly from the craftsman that make them. Every piece that I perform has my personal touch to it. Often it is tweaking the method to suit my needs and coming up with my own presentation.
I think what Josh really is talking about is performing other people's material without purchasing the material or otherwise having permission. My sense is that if it is good enough for you to perform, it is good enough to purchase.