Lay your jacket out and zip up all the zippers.
If your jacket has hook-and-loop tape, fasten it closed.
Don't forget to check the pockets for any treasures or love notes you may have forgotten.
Place the jacket in your washing machine.
Add technical wash specifically designed for down garments.
Each brand of technical wash is different, so you'll need to read the label on your bottle to know how much to add.
Set the load size on the washing machine to small.
Set the water temperature on the washing machine to cold/cold.
Run the washing machine on a gentle or normal wash cycle.
Leave the jacket in the washing machine and run the rinse cycle a second time.
Remove the jacket from the washing machine and place it in the dryer.
If you don't have a dryer, or would like to go a more environmentally friendly route, line dry your jacket.
Add a couple of tennis balls to the dryer.
The tennis balls will bounce around as the dryer tumbles, preventing the down from clumping.
Set the dryer on a low-heat setting with a normal dry-cycle time.
Start the dryer.
It may take more than one cycle on the dryer to completely dry your jacket. If so, leave the heat on low and dry for a second cycle.