Niantic, please give us more ways to earn rare candy

So many legendaries, one power up is like a two weeks raiding for a regular player, especially for those of us who've come back in the past few months and are getting legendaries from research rewards.

Some ideas:

Trade in useless or excess candies for rare candies at say 5:1
Obviously more candies from raids
Rare candies from gym victories
Waaaay more field task candies eg. excellent throw = 10 candies; great throw = 5 candies etc.