Church wedding flowers have to be big to offset tall ceilings and big spaces. If you are filling large spaces, even arrangements with nothing but greenery are beautiful and very cost effective.
Greens can be done several days in advance. Simply spray with a leaf polish when finished. Do not spray Leafshine on flowers, however, there is a gentler sealant made especially for flowers.
Greens may need to be washed when arriving dry packed from the field. Hard water tends to leave a splotchy white residue on leaves.
Leafshine removes that and leaves a cleaned, glossy finish that lasts a long time in regular temperatures. I do have smaller cans that are available so is cheaper for a single wedding.