I freeze leftover shells when I make orders for clients and have extra shells - that way if I need some for a cake order or for sample boxes (weddings) I have spare shells on hand. I thaw in the fridge and then fill.

@Adrianna Kirchhoff I put them in containers unfilled and have left them for a few months and they've been fine.

I tend to do a ring of swiss meringue buttercream with the filling in the middle (lemon curd, caramel, chocolate fudge etc)

Oh she's beautiful!! When I set up my cake studio the oven was my most exciting purchase. Mine is electric convection, and I'm able to bake 4 full sheet pans in her at a time. My macaron mats hold 70 shells each (so 35 full macs) per tray. I do tend to rotate the pans halfway through baking (not rack to rack, just spin the tray so the back row is a the front of the oven) to get a bit more even with the feet.

@Heather Ioa amazing - I totally stink at the airbrush!! I do have a direct to food printer that I use for printing on macaron though - love this idea!