Great question. Washing plays a huge part in the environmental footprint of your clothes, so it's important to get it right.
Activewear - Wash inside out in a delicates bag to avoid friction and damage from the washing machine. Preferably use a guppyfriend bag. Line dry. No iron, bleach, spin dry or softener.
Jackets - These don't require washing often, perhaps at most a couple of times a year (only with heavy use). Cold machine wash, preferably in a Guppyfriend Bag. No iron, bleach, spin dry or softener.
Organic Cotton - Cold, gentle machine wash with similar colours. No bleach, softener or spin dry.