Before you pitch, see if you can find out how often the investors actually fund something. Also find out if the investors are full time investors, and how large the fund is, how large the firm is. I could be wrong, but I’d guess a first-order rule of thumb is the seriousness of the investor is more or less proportional to the size of the firm & fund.
I don’t know if this is what parent was referring to, but my town has a seed fund that calls themselves “angels”, but they’re not full time investors and they have a low rate of funding anything, and when they do it’s for small amounts. My business partner liked to call pitching for them “doing dinner theater” - it was literally in a restaurant. They were fine people, but they had very little idea of how to identify a good startup, and so pitching for them was both difficult and fruitless - they also didn’t really have any good advice or connections to help. It was weird, but pitching for larger funds was way easier, the larger the easier in my limited experience. The goal posts were clear, the rejections were quick and easy and helpful(!), and they gave us real and practical advice, and btw told us exactly why we were asking for too little money.
Experience pitching will reveal some things about the different kinds of investors. Aside from gauging the group of investors, probably the only other good advice I have is go around asking a bunch of people what they think about an investor, you can glean a lot from learning about people’s reputations. (Note that goes both ways - investors talk to each other and you will have a reputation soon enough, so keep your record clean!)