Ask HN: How to avoid the biggest tech co-founder pitfalls?

Are there any guides for tech co-founders who are managing the architecture, planning, hiring, for the first time and cover the biggest pitfalls (eg painting yourself into an architectural corner, technical debt) and how to avoid them?

Even if its with non-technical solutions like having a mentor etc. Just the big ticket items. It needn't be too nuanced but any advice appreciated.