• If your co-founder repeatedly makes misleading or false statements and it makes you uncomfortable (e.g. to the media, co-founders, investors, etc.), talk to them about it sooner rather than later.
• If you don't know your potential co-founder, then call their references! These will be the same references they provide when fundraising, so it will doubly help your company succeed.
• Leaving 100% of the legal and 100% of press interviews to your co-founder is a very bad idea. This makes it very easy for them to throw you under the bus.
• If your co-founder makes seemingly illogical decisions, ensure you understand why.
• Don't let your co-founder continually delay important things at your expense, even if they provide excuses. For example, not putting things in writing, not giving you equity they promised, etc.