It's a little bit of a balancing act and is 100% all about the size of the operation. If I'm on Etsy and find a good product that can be sold at scale, I usually start with a well-worded e-mail explaining my plans and see if I can negotiate a price point that works best for both parties. I usually don't try to drive the price down too low because, in this scenario, many times the maker themselves are already selling on a margin and the biggest opportunities a lot of times come from people that are already underselling themselves.
For medium-size operations, the products are already mass-produced and they'll typically have their own sales staff that you can call directly. This is the most untrusting of the three, and you'll have to display competence in the industry. You'll want to discuss "online retail operations", not "dropshipping". You'll want to ask if they offer "shipping solutions" and if they work with Amazon FBA. And above all, be honest. It's hard to score when you're just starting out, but with persistence, you'll find someone that will work with you. If you begin with an honest relationship, any sales manager worth their salt will go to the ends of the Earth to do everything they can to make you successful.
For the largest distributors, more research is usually needed. It's easier to start with a product and find out where it comes from rather than randomly searching. For example, take Pioneer, maker of electronics and sound equipment. On their website, they list their "authorized internet dealers" which is essentially a list of retail stores AND conventional distributors that offer the product (
link). So I take that list and find the smaller operations first and just start making calls just like I do above.
For the most part, it's researching a company, calling a company, and getting a rejection. Out of a list of about 200 places I've contacted, I ended up with only eight companies I'd be able to and want to work with, and only a couple that I actually order from. Oh, and quick tip. When calling a lot of these companies, quite a few won't even start a discussion unless you have proper tax numbers. A company not asking for these numbers is actually a personal red flag for me. Most major legit operations will be asking. In my experience, the payoff of working with actual distributors far outweighs having to pay taxes, but that's just me.
