Build the round around hard deadlines first. A wedding at eleven and a funeral at two are fixed points that everything else has to fit between, and treating them as ordinary drops is how a shop ends up delivering condolences after the service has finished.
Capture the card wording as carefully as the order. It gets dictated over a phone, often by somebody upset, and it is read by the person who matters most — so it needs confirming back, not scribbling on the same pad as the address.
Plan the peak days as separate operations. Fourteen February is not a busy Tuesday: it has its own stock order weeks earlier, its own staffing, its own delivery windows and its own cut-off, and shops that run it on the normal system spend the day answering the phone instead of making up orders.