Everyone agrees you should build an MVP. Far fewer agree on what one is, and that confusion is why so many MVPs fail at their actual job. A minimum viable product is not a cheap version of your product; it is the smallest experiment that answers the riskiest question behind your idea. Build it with that definition in mind and it saves you a fortune. Build it as "the product, but smaller" and it wastes most of what it costs.
Step one: name the riskiest assumption
Every new idea rests on assumptions, and one of them is more dangerous than the rest — the one that, if it turns out to be wrong, means nothing else matters. Usually it is a version of "people have this problem badly enough to change what they do about it." Before you design a single screen, write down that assumption as plainly as you can. The entire purpose of your MVP is to test it as cheaply and quickly as possible, and naming it keeps you from building things that test nothing.
Step two: design the smallest test
Now ask the uncomfortable question: what is the least you could build to find out whether that assumption holds? The answer is almost always smaller than your instinct. Often you do not need to build the whole solution — you need to build the part that proves people want it. Strip away everything that is not essential to the test: every feature that makes the product "complete" but does not change the answer to your core question is, for now, a distraction you cannot afford. This is the hardest and most valuable discipline in the whole process, because every stakeholder will argue their favourite feature is essential.
Step three: build it properly, but small
Minimal must not mean disposable. A common trap is building the MVP so cheaply and carelessly that it cannot become the real product — so a successful test forces a rebuild from scratch, and you pay twice. The better path is fewer features built on foundations you would be happy to keep, so that if the assumption holds, the MVP grows into the product rather than being thrown away. You are not building a throwaway prototype and you are not building the full thing; you are building a small, real first version.
Step four: put it in front of real users
An MVP that only your team and your investors see has not done its job. The point is contact with reality: real users, ideally strangers who match your target, using the thing and behaving honestly because nothing is at stake for them socially. Watch what they do, not just what they say — people are polite about ideas and honest with their behaviour. This is where the MVP earns its cost, by replacing your confident guesses with evidence, some of which will be uncomfortable and all of which is worth more than another month of building.
Step five: decide, honestly
The MVP exists to enable a decision, and you have to be willing to make it either way. If the evidence is strong, you now build the real product with confidence and a clear idea of what matters, which is the best possible position to spend real money from. If the evidence is weak, the MVP has just saved you from spending a fortune building something the market did not want — which is a success, not a failure, however it feels. The teams that get the most from MVPs are the ones honest enough to hear a "no" and change course, rather than treating the MVP as a formality on the way to building what they had already decided to build.