1. If you're talking/doing business, get everything (as much as you can) in writing. Even if it's a simple email to confirm or clarify the agreement.

I get a lot of calls for advice, and one of the most common scenarios is lack of proof of an agreement between two parties.

2. Always assume you'll need proof of an agreement.

Relationships - even the really good ones - can go south very quickly. Protect your sanity, time and money by having a clear communication trail that can be referenced if anything goes wrong.

3. Phone calls can be denied, an email/chat cannot.

Verbal agreements or gentleman's handshakes are good for quickly agreeing on something. But if the stakes are high - and even if they're not - always have something in writing.

A phone has no records, but emails have trails.

4. This advice is especially important between friends or casual business deals.

I struggled with this - and almost lost a few good friends - because we assumed we'd work things out. People have priorities and people take advantage.

Always have very clear expectations.

I hope this is helpful. What other lessons have casual engagements taught you?