Itry to avoid the holly as I HATE it - brings me out in aa rash. I buy branches of blue spruce and use this for the basis of all my arrangements.

I make my wreaths on an oasis ring - DO not be lured by the cheaper varieties as they will split on you.

Use viburnum, rosemary, eleagnus, tree ivy, box etc - can be made up all throughout Nov and kept covered with plastic in garage.

Just stick to one size and think of a few themes ie tartan, winter wonderland, & name your wreaths etc and get ready loads of the accesories to suit. Make bows in advance too.

Make up matching table decs with simple pots - even spray teracotta, chunky candle in the middle, cinnamon sticks walnuts/chestnuts, break down some sparkly twigs to put through it - these walk out the door.

Most people have already said, make up LOADS as no one will want to wait.
Make up a really wacky wreath for your shop door - made entielry out of quality street sweeties -even if you don't sell that design it will be a real talking point.