Dahlias?

To store them, bury them under a privet hedge for the winter as it's always dry there.

I bought one yellow stickered crown of Vancouver (flowers are red with white tips) and now have six plants taken as cuttings from this single crown. The crown (which still has loads of shoots) will be planted in the garden to brighten my autumn days and the cuttings will be planted at the allotment for cut flowers!

I'll have to wait to see whether any are worth saving Vinny, they're only ones I've grown from seed. Dwarf Dandy and Pompone Mixed. Knowing me they'll just get left in the ground and take their chances.

I make sure my tubers are thoroughly dried out. Dig up and dry upside down in the greenhouse. When dry, brush off the mud. I wrap in newspapers and store in boxes. Any sign of wet and lots can rot off. If you have enough - storing in perlite/vermiculite is a good option.
My Aga when taking it out was filled with vermiculite. I've used that to store some of mine. They were perfect when I took them out. Unfortunately the newspaper wrapped ones got mice in!

JJB - I don't grow the bedding types but pinching out encourages side shoots. I always pinch out the tops of my dahlias.

I have pinched or snipped the leading buds, they had blackfly so it served two purposes.