Build, not burn those bridges

The entrepreneurial world can be quite small sometimes, and it's very important to build relationships in it.  These relationships become the foundation and resource for solving problems that your company eventually encounters, whether it's raising money, finding a strategic partner, or finding a key employee.  A large component of a company's ultimate success stems from its relationships.  And in this ever-increasing world of social networking, it's essential that these relationships are maintained and never burned.  If you don't like the fact that a VC kicked you out after just 10 minutes, or will only offer you ugly terms, or whatever, just walk.  Don't retaliate.  Keep that relationship, because you might need him in the next company you start.  Or, he might be contacted by another VC you're pitching, and you need that positive reference.  Same goes for relationships with employees, employers, business partners, etc.  Do you have a particular experience you'd like to share here?

Chemistry is important

I'm not talking about chemical bonds, but human bonds.  If you're thinking about starting a company with a friend, colleague, acquaintance, spouse(!), or otherwise, make sure you all are on the same page with respect to your vision for the company.  This includes initial product features, product roadmap, market niche, market strategy, company structure, company ownership, who's in charge of what, and a method to resolve conflicts, which inevitably will arise.  I could go on, but you get the idea.  Equally, investors look for this same chemistry, not only between the founders, but also between the investor and the founders.  If an investor gets a funny feeling about his/her interaction with the team, the potential for investment may be in jeopardy.  So be sure to start out right by building a team of entrepreneurs who are all in sync with you and are team players.