Just a quick rundown from my perspective as a founder. Don't consider any of this the final word, of course.
Above all, if I like it, see the benefit and have the money for it, it doesn't matter how you approach. Be straight up about describing it and the benefit to increase the chances of this happening.
a) Cold call/email -- call will probably go to voicemail and I might not get back to you. Email will be read and I will reply with a "no, thanks" or with interest (please note I am not at all behind on my e-mail like some people are.) I much prefer text-primary e-mails to "newsletter" type e-mails that seek to educate me before describing the product. I really like it when someone's e-mail says that they won't e-mail again if I don't respond, but it doesn't influence my decision.
b) Yes, if you meet me you should obviously describe what you do. I will want to hear more and probably make suggestions even if I am not interested.
c) Sample will work really well if it's something people want. Information without a sample has a chance of getting binned. Putting a very visible offer on the information would get more attention from me.
d) Bad idea. You don't know enough people to make this go. You need feedback from strangers.
e1) Look for partners complementary to your business. For example, if you do fresh flowers, get in with an office cleaning company who would sell your flowers as an add-on. They'd get a cut in exchange for you not having to sell.
e2) Also, despite what I said about annoying "educational" newsletters, you should definitely do that on your website/e-mail signup on your website. Some people will definitely find you, even if it's a new product category without a popular search term yet.
e3) Please promote yourself on Hacker News. What is this product/service? Tell us about it, and leave a way to contact you.