How do I Collect coins?

You don't.

Your coins are given to you when your pokemon is kicked out of the gym.

Would you like to know more? :)

https://support.pokemongo.nianticlabs.com/hc/en-us/articles/115009004687

My Psiana Just returned after 32minutes, brought ne nothing.

What is.. i don't know.. Sure if it always would instantly return coins, you and a friend could get your 100coins within 10minutes in 1 Gym..

But as i often sieged some gyms and instantly collected after getting the Last gym for the day.. it's Kind of useless now to only get a Gym to lose it again?!

Well.. i guess niantic just saves some coins with it.

Or did i get something wrong?

Just checked again. Lost another Gym after exactly 2hours. Got 2 coins for it.

This means you need to keep a Gym 10 hours to geht the 10 coins you got a week ago in an Instant.
In the other Hand.. of you find a lonely never visited Gym i assume you can get 24 coins/das instead of 10?!?!?!
Anyway...I don't Like it.

two of my mons returned, I got one coin each.
They were in each a gym for more than one hour but less than two hours.
My other mons returned in less than an hour and I not nothing.

I gotta admit I am a little disappointed with the new system...

This system rewards doing the gym run "last" so late late night when you can sit there for a few hours before the morning players go...

If you get knocked out within 1 hour, you get nothing and 1 coin is pretty pathetic...Also, with 6 gym spots, it'll be hard to get a spot I feel...

I sorta liked the old prestige thing since at least you needed to use some skill to prestige fast (the only previous thing which required some skill IMO) and you were rewarded...(as I was always the player which had to do the 8k prestige)...

Now, you'll get coins if you do a gym run as the last player to do it (to prevent getting knocked out in 1 hour)...

If you are in a dense city, you will NEVER EVER get coins now...

I suppose I should be glad I didn't spend to get another lucky egg pack (already got 40 eggs) since Pokecoins are going to be super hard to get IMO. Motivation decay seems super fast as well...

I think I will end up doing less gym battles now honestly.

I suppose I can feed berrys to everyone elses mon...