Three good ideas from the book:
1. Nail the problem: Talk to your customers - a lot.
2. Nail the solution: Experiment/prototype/analyze/iterate
3. Nail the scale: Scale only when the time is right and business model/revenue streams are figured.
To add, we're between 1-2 right now, and few weeks ago, we provided our product solution free of cost to companies and expected this was a good idea - since there was no friction for them to use it so they'd at least try. But we realised that these people were not serious about using it, did not value it, and provided almost zero constructive feedback.
One personal takeaway just was to have our customers pay us from Day 1. It is really a counterintuitive but great advice: people associate higher value to goods that they pay for, and for you as an entrepreneur, it really puts the customer you want to target in clear sight. Also, the paying folks are great for advice and uncovering painpoints - because they're very vocal about what they like or dislike - they're paying us after all and no one pays for something they don't want to use.
Since the time we've put a price label to it, we've already found good customers, who're ready to pay us, and boy, they are very gung-ho what they like or hate about it! Time to rejoice and build better!