Originally Posted by Atik L Yar
I was under the impression I wanted to initiate fights with my Ult, rather than save it.
I'll be sure to try holding it back more.
In most cases that IS what you do, but for enemies that will easily escape, you want to be SURE not to allow them to run. I mean high mobility champions or champions with stealth; you don't want to get into a fight and blow your ult without knowing that you're going to be using it, especially not early game, so I figure it's safe to say that saving it for the exact moment you're going to use it, given the opportunity against said mobile champions, is safer and more subtle than just going in with it open. There's always the possibility that they'll just run at the sight of you.
Otherwise though, you do want to initiate with your ult, the 20% damage steroid is an incredible amount of damage output with any good build. If you don't think they'll be able to escape then go ahead and use it the whole fight.
I never found it to be much of a problem either way though. Riven's a good champion for forcing enemies to fight or die and half the time you'll be more of a priority to kill than the adc.