Accessory tickets are only usable once, and cannot be regained once they have been attached. They provide a visual alteration to your armour and helm, varying from flies permanently buzzing around you to Wolver tails that attach at the back of your armour and scarves that trail behind you to flutter in the breeze. They don't make your gear any more effective, except maybe in PvP if they make someone go all 'whoa nice armour wait you just stabbed me to death while I was trying to figure out what accs you were using asdfewlewark'.

Even strata drop more crowns than odd ones.
Graveyards and Arenas are crown- and heat-rich levels.
Treasure Vaults are rather less rewarding than their names would imply.
Danger Missions are extremely rewarding, although as their name suggests, they are dangerous.
Boss levels are also very rewarding, with tokens that can be exchanged for equipment.