If you have the ability to record your annoncements (maybe using a Sansa clip at $20 that has a voice recorder), that will be an eye opener.
Once I did that, I found that I needed to slow down...it will sound in your head like you are talking too slowly, but you really are not.
Or , at home, just record yourself reading a list of BP intros from a prior wedding like you would at an event with all the inflections that you normally use.
Listen to that and be bluntly honest with yourself. Do it again correcting the mistakes you made the 1st time. Do that over and over.
Oh, and don't use the phrase "At this time...". I've heard it said over a dozen times at events I've attended from various DJ's and it sounds (IMHO) so boring and without thought.
Try using other phrases only once...keep it varied and unique to that event.
Oh, and it's ladies and gentleman, not "gennelman" as I've always heard. Make it a point to enunciate, speak slowly and with a little lower register as that will carry farther.