Tip 52: Product - secret sauce. Angel groups don’t sign non-disclosure agreements to receive information – so don’t ask. If you do, you lose credibility from email #1.
(Very rarely, we will agree to sign an NDA during the diligence process if you’re sharing the recipe of the secret sauce – but this is extremely rare. I can only think of one example, where a single member of a diligence team signed an NDA to hear the identity of a major customer, which could not be revealed because it was a public company. I can't think of any for tech-coverage.)
This should not be a problem for you. If it is, we are not the right investor. If you won’t engage without an NDA, we are immediately told you have unrealistic thoughts about your technology and don’t understand how to protect it (you realize patents require you to put the secret sauce in the public domain, right?).
In general, don’t share the secret sauce's recipe. We probably aren’t going to be digging into your code (or whatever) anyway – but don’t be too secretive about it, and tell us what we need to know in order to advance you to the next stage of the process. The secret sauce isn’t worth anything if you can’t raise capital to sell it.
For the pitch itself, you need to strike a balance between being convincing and exciting, but without revealing too much, while avoiding being in the weeds and violating tip 50. Not easy, so practice a few different versions of the slide and pitch until you find something that strikes the right balance.