Drying, and the heat that costs you
A tumble dryer is the harshest thing most clothes go through. The lint trap is the garment: those fibres came off the cloth. Lower heat, shorter time, and out while barely damp.
What the heat does
High heat degrades elastane, the fibre that gives leggings, socks and waistbands their recovery. It also sets creases and shrinks cotton by pulling fibres back on themselves. Most shrinkage blamed on washing happens in the dryer.
Out while damp
Take things out slightly damp and finish them on a hanger or a rack. It cuts dryer time substantially, removes most of the ironing, and is the single easiest change to make.
Never the dryer
Wool, silk, anything with elastane you care about, bras, and printed graphics. Wool felts with heat and agitation together, which is exactly what a dryer is.
Dryer balls, honestly
Wool dryer balls separate the load and shorten drying time a little. The claims beyond that are thin. They are cheap, they last for years, and they replace dryer sheets, which coat fibres in softener and are what makes towels stop absorbing.
