"Alone we can do so little; together we can do so much" Helen Keller.
You know what! Without a great friendship, you can't collaborate well, especially in business startups. A great business is founded on great partnerships, sometimes businesses can also be destroyed by bad partnerships. I am an advisor to startups, I often get asked how to choose the best co-founders. My first response is that it’s much like finding a lover or a spouse, the chemistry and complementary communication skills are key.
The first thing you and your potential co-founder must define is who will be responsible for what, once you have these points ready, it's time to start the game.
Get it on Black and white, avoid "He said and she said "
You should also absolutely, 100% take your time, but once you conceive the idea and it's solid then the next important point for startups is documentation. Create a basic document of understanding. Once we write it down our brain is set to think and stick with that. Make sure that all partners have receipts in any communication done."It's better to be early rather than later" You and your co-founder should spell out early on what your monetary compensation will be.
"So time to date" I would recommend you meet with them multiple times in different social and non-social settings, this includes outside of a business meeting. (Remember, you don't know him/her, so make sure it's not just the business mask they’re showing you.) You should also get to know their friends and family. Figure out their personal priorities and the things that motivate them. Again it's not a one day job or even a week's job. Remember "there will be financial and legal commitments on the pipeline".
Rather than being a helper.
This means you need partners who are smarter than they are in respective domains. For example, a great business visionary needs a techie or a strong salesperson who is willing and able to make decisions. You need to believe that you can learn from them. They need to have different, complementary skills to your own but share the same vision.
Is your partner, your business partner?
Make sure you have a clear understanding, unfortunately, life is not always as rosy as what we see from the outside. Money, power and love are key details that should be outlined early on. For example, if one of the co-founders is leading the sales process, you have to decide: will they be making a commission? What will your salaries be early on when the company isn’t making any money? What will you do if you want to sell your share of the firm, who will have the first chance to buy and how will the price be calculated? All this has to be in a contract and including a memorandum of understanding that is duly signed and witnessed.