Prioritize Opportunities, Not Solutions is a really good post by Teresa Torres about using the Opportunity Solution Tree methodology to make sure we place lots of product bets early on in a lifecycle, and only implement the ideas that matter. I also like her distinction between one-way door decisions (“once you’ve walked through the door, you can’t turn around and come back through”) and two-way door decisions:

Your opportunity assessment and prioritization decisions are two-way door decisions. Once you choose a target opportunity, you’ll test whether or not you made the right decisions by prototyping and experimenting with solutions that address those opportunities. If you learn through experimentation that you didn’t choose the best opportunity, you can always walk back up the tree and choose another opportunity.