Centerpieces, Favours For Guests.

I think I have finally decided on centerpieces, but I am doubting myself because I don`t know if they will be fancy enough. Also, there is still 8 months til my wedding, should I hold off? As for favours for the guests, how much do I spend on each person or each couple? This is not a huge fancy wedding, but I still want it to be elegant and not seem cheap. Just hoping to stir up some discussion and suggestions....thanks