I think shooting to spec guides you, Aacb, whether its someone else's notion or yours.
If you've got only picture about an event that you're going to print, submit to social media or whatever, it's got to be the one that when flicking through the contents of your SD card captures its spirit better than the others, even when the others are technically better.
It can be you and your wife on the gondola, or the celebration of a tennis player winning. (An editor is more interested in Djokovic on his knees than all the action shots beforehand … you can turn up an hour and a half late to the game and still keep the publication happy!)
With two shots, you've got more scope, so you can be more inventive and go for say, the wide shot and the close up shot that you like best.
With three, you've now got narrative possibility … context setter, followed by a picture of the subject, then the climax or resolution of the scene, the money shot.
So a lot of self-editing has to enter into it. Nothing worse than looking through someone's pics and it's clear that for two hours they just stood on the same corner and got the cars all going round it, pressing the shutter release again and again.
Having said that, it's not enough either just to get one shot from ankle height, one from standing up on a park bench, another shooting through bystanders, another backlit, etc, because for each setup you need to take lots of frames and then go through and put a keeper star on the pics which best capture the moment. Someone walking looks best when their front foot is down on the ground, for instance, so you'd try not to use the frames before or after that.
In short, I reckon, think not just as a tog on the day, actually shoot from the beginning aware of your role as an editor of these pictures later on too, and there'll be real purpose to how you go about this great hobby of ours.