One of the hard things to know is whether to undersell or oversell. When in doubt lean towards underselling. (If people catch you closing, you can be doomed).
The risk of overselling is that you insult the intelligence of who you’re dealing with. You risk not respecting them. You risk oversimplifying things.
The risk of underselling is that nobody knows what you’re about. You don’t talk about how good you are and aren’t charismatic or compelling.
You have to constantly tune. The damage created by overselling is far more severe than the damage completed by underselling. You will rarely get a second chance if you insult a man’s intelligence.