Dreamly Defocused background suggest mystery and romance - and few tools conjure them up as effectively as the shallow depths of field possible at f/1.4. No wonder you cannot dig too deeply in any wedding photographer's bag before bumping into a 50mm f/1.4 "detailer."
It is useful for focusing in on table decorations, the bride's gown and jewelry, the bridal bouquet, and other ddetails, since that f/1.4 aperture successfully throws everything but your subject out of focus. It strongly forces viewers' attention to where you want it, simultaneously casting an irresistible, soft spell over everything else.
Shooting at f/1.4 can be magical, but it is not easy. Holding the focus on elements that need to be sharp can be challenging. (The closer the focusing distance, the shallower your depth of field becomes and the harder this gets.) So, when working at or near maximum aperture, be careful where you are focusing. Don't pat too much attention to the green "in-focus" viewfinder bullet. Instead, keep your eye peeled to the specific AF target that's active.
Don't automatically work at f/1.4. Closing down a stop lessens vignetting and expands the depth of field for sharpness, while still delivering softness beyond. And, since 50mm f/1.4 lenses are typically least sharp when used wide open, if detail is important (as in flower close-ups or eyelashes in tight portraits), again, stop down a bit.