Code Shares and Scope

Hi All,
Looking for some honest info and learning from the benefit of hindsight from those that have been there already.

If your pilot group were at the beginning stages of considering allowing code sharing / partnership flying how would you proceed? Would it be a flat no? Would it be in exchange for certain terms? If so, what would they be? What are the pitfalls? What are the benefits?

No flame intended, just looking to hear other's thoughts and gain some wisdom from experience.

Thanks