The buzzword in the early 2000's was "synergy" - when two things come together to create something that is greater than the sum of their individual efforts. It was used heavily and eventually became jargon that you only hear from the folks at the top of huge multinational corporations. They haven't heard that the word has been played out. Now the word is collaboration, which essentially means the same thing, and it is one of the biggest tools of success for any entrepreneur.
To collaborate is to understand that you, as an entrepreneur, don't know everything. Maybe you have incredible idea for an app but don't know how to build it, or you have the idea and can build it but you don't understand the market, or any other weakness that you might have. You have to be cool with saying, "I don't know something". It's not a failing, it's moving forward.
The second piece to collaboration is to realize this is not "my" project anymore. There is no time for "this is my idea" because, if you want to collaborate on something, it truly has to be "our" idea. There must be a balance of power, no manager or employee. Even things like who takes notes or who's office you work at can change the power dynamic. When you are manager and the other person is employee, you are not collaborating, they are working for you - the end goals might be similar but they are different. The manager wants to maximize profits and see a project completed and the employee might want the company to make money and get a project finished but they ultimately want to just continue working. Stepping up and realizing that this is a true collaboration between people with the same goals but with different expertise is key.
Next comes the trust, when you both admit you don't know how to do something and completely give up control of that piece. There is no looking over the shoulder, there is only trust - you are collaborating because you are not as good as the other person at this, so you forfeit that piece. It's doesn't necessarily have to be a scary thing, it should actually come as a relief - that portion is being handled by someone who knows how to do it better than you. It's kind of a nice feeling.
Transparency is also incredibly key to any collaboration. At this point you need to be able to trust each other and make realistic expectations for the work. This is all a function of the trust piece, you are now the authority on what you were delegated, meaning the other partner trusts your judgement. Be sure to let your partner know what is realistic, what you can and cannot do, when it can be done by and what resources you need. The more open the conversation and dialogue is the more functional the relationship will be.
Keep in mind that collaborations are not all smiles, there will be tension and hard conversations, but that can be extremely productive. You are not there to hang out with your friend, you are there with a goal in mind and, for you to reach out to a partner in collaboration, there must have been a problem you could not solve. Often you will choose a partner out of skill or intelligence only and your personalities clash and that's ok.
The final piece is credit. Once a project is completed you still have to realize that this is not your project, this is a team project. This means there will be less credit for your individual work, but that is all a part of leadership. It's also an issue with the inherent trust that goes into project like this - the trust is that you, as an entrepreneur are truly turning "your" project into "our" project. If that trust is broken than the whole project and the trust that goes into that relationship has been undermined.
Collaboration is tough but can be incredibly rewarding if the partners are able to go into with these things in mind. It takes mature leaders to be able to truly understand that with a partner they could create something greater than they could achieve on their own.