Do Your Research!
Do a little bit of digging and you can turn up a world of information and reviews on any dropshipper you can think of. Remember to not only read the reviews, but find out where the review comes from; most companies 'seed' review sites with their own positive feedback in order to drum up more users. Although this doesn't necessarily make the company bad, it is something to keep in mind if you are looking for unbiased reviews. Ask other internet business entrepreneurs what they're using and why and what companies to avoid and why. Compare prices, services, how to contact the company and anything else you may need to use while working with your dropshipper. The more thorough you are in this stage, the happier you will be with the final results.
What are you Selling?
Have a very clear idea of what kind of products you are selling while tracking down your dropshipper. Most dropshippers specialize in a number of products to ship for you, so you'll want to narrow down your choices by what you're selling and cross-checking it with your shortlist of dropshippers to make sure they'll accept your goods and know best how to deal with them, especially the more fragile objects.
Once you've figured out which dropshippers are legitimate and which ones will ship your products, then pick two dropshippers, one as your primary and one as an alternative in case your primary dropshipper falls through or no longer works for your business. This way you'll always be able to ship your products and your consumers won't run into empty virtual shelves or have to wait longer for their goods.
Finding a good dropshipper is mostly a matter of time and research, but once you have that company, you'll have a great deal of stress and worry lifted from your shoulders. It's well worth putting some effort into your research for the ideal dropshipper and it will really help your profit margins at the end of the day!