With Spring bulbs and Summer flowering shrubs making sure those seasons work in the garden, designing for Autumn needs to be subtle and draw upon not just colour but textural and tonal contrasts.
This first picture below I took in West Sussex at Petworth house. A very good hot coloured combination as the weather gets cooler.
The Cardoon, purple Asters and Miscanthus grass is one of my favourite combinations for a late Autumn border, majestic and detailed.
Sedums and silver Artemesia provide a vivid backdrop for the sultry coloured Chocolate Cosmos