Be careful with the selection process for user interviews: You might end up picking those that will support your vision – it’s a self-fulfilling prophecy trap.
Beware of false positives in user interviews.
Never start writing a single line of code before an appropriate number of customers signed up. (For clarification: Customers are paying users.)
Never spend money on developing a prototype when you’re not working full-time on growing the user-base and increasing customer value.
Be patient and give your product the time it needs.
Always make branded t-shirts and wear them later regularly to preserve the recollection of the disaster. (See below.)