I may suggest that as you have to handle so many delicate flower heads, it is always wise to wash your hands to remove any dirt or natural skin oils that can brown or damage petals.
I usually mist my fingers with Finishing Touch so I don't leave any bruise marks on the rose heads.
If any blemishes are on the roses, simply peal away the offending petal until each rose looks perfect.
Roses are pretty hardy and can take the handling. Other flowers like freesia and stephanotis have to be treated with great care as even the slightest crease may cause browning before the wedding ceremony.
The bouquet is complete and ready for a good misting of flower sealant and for the stems to be locked into place with Floralock.