If you are making your own wedding flowers, be sure to invest in a few fresh flower products that are used by professional florists. Products like flower food and sealant products aren't that expensive, but can make a huge difference in extending your flower life.
Florists store their finished designs in coolers that put humidity INTO the air. Home refrigerators and air conditioned rooms can be cool - but they are designed to take humidity OUT of the air.
This hydrates thru the petals and slows evaporation, which is the first step of flower deterioration.
This arrangement looks nice anywhere you need a design that is kept low to the table.
You can add instant elegance with taper candles. You may want to use candle stakes. These are inserted into the top of the foam before greening and makes it so you don't have to poke the candles down into the foam (which can hit flower and greenery stems and push the flowers out of place.)
The stakes have sharpened points that push easily into the floam. Then you continue to green around it. Later - at the reception hall, you insert your candle into the stake.
It is not good to transport flowers with the candles already inserted. They can wobble and move around during delivery and cause the hole in the foam to "wallow out" and make the candles tipsy. There is always a chance the centerpiece could shift while in the vehicle, breaking the candle.
Cluster in more candles if you wish, staggering the heights to suit your own taste.