Be frank with you co-founders

If you are too cowardly to have difficult conversations with your co-founders, you have no business starting a company

via Lessons I Learned from Co-Founding a Tech Startup.

If you are thinking to start a company with your friends or anyone else. You have to make sure that you can have a ‘real’ conversation with them. i.e. if your co-founder has done a wrong thing, you would need to point it out to him because it is in the best interest of the company. The most important thing after having a conversation, it is to trust your co-founders.