This is a meter from my last run I did with a LFR 25 man, I seem to be doing better but need work still:
This is a log post of Garalon 25/10 attempts. We are not the greatest guild so don't flame :P. The More AOE, the more you will get out of BoL. Holy Radiance + Holy Shock is a pretty nifty combo as well. As your gear progresses, you'll find you will be able to cast the big spells a little more frequently but at the moment, you have to play conservative and rely on other healers as well. Don't feel like you need to absolutely top the meters every time. As long as you aren't falling behind tanks/dps, you are doing something right.
All in due time.