I'd recommend a couple of things here:
1. Make sure you go into a vertical that isn't completely saturated. Make sure your product offering and value stands out and isn't in a sea of similar options. Trademarking and patenting can also be great tools to keep people from encroaching in your space, but it isn't full proof and there's tons of ways for people to get around it. More important here is to establish yourself as the original and first market leader
2. Focus on scaling sustainably and profitably. This is one of the most important things buyers/investors will look for. Gone are the days where unicorns that lose as much money as they make are being snatched up or seen as valuable. You want to prove you can build your business and that it can last 100 years on its own
3. Build a defensible position: Establish marketing and business building tactics that make it very difficult form competitors to come into your space. For example if you , you can negotiate category exclusivity in some areas so your partners can't work with any of your competitors. This is immensely valuable.