When GMing, there are certain times when you flip a Destiny Point according to the rules. Things like "Helping Hand" and "Raising the Stakes" are listed on p. 26, as well as various talent uses and so on.
Infrequently a GM might use a Destiny Point as a narrative aid, but this seems a bit unclear to me. I mean, the GM can say that the weather is bad and have people take disadvantage, or roll vs. Fear, and so on, without having to spend Destiny Points.
In the game I ran last weekend, the players were using Destiny Points very quickly, and I couldn't find any reason to use any to add to the pool. They spent down to 1 Light Destiny Point remaining, and then held it "for an emergency".
Do you ever just flip a Destiny Point? Without doing or saying anything, and just let the players think something major has just happened, something they missed? I could see doing that, but haven't.
So, when the players have spent themselves dry, how do you keep those Destiny Points flowing?