quickenings

So I have a quickening for each of my characters, they are level 25-32 (yay for keeping Vaan and Fran in my party at all times). But I can't figure out how to "chain" quickenings like everyone is talking about. The screen flashes fast so quick I can't seem to figure out how to link them...

Alright, have had a blast so far playing, but then... I am getting so frustrated with these Quickenings. It's like, I use one, and hit R2.. and nothing fucking happens. The names cycle so fast that I can't see what's up, it's fast enough to give a man epilepsy. After three furious attempts, I...