How do you acquire special items?

Low chance to get an item every time you spin a pokestop.
More rare than chickens teeth.

U can get those items in pokespots during normal times, got a sun stone yesterday, spin 1 in like hundred chances... very rare

My experience is based on 3 items. 2 came from first spin of the day bonus (7 day streak and 5 day streak) the other was a standard pokestop spin

I got one on a random spin earlier this week. Hit my 7-day streak yesterday and did not get one. Seems to be just random with a better chance of getting it on a first of the day due to more items.

They removed that evolution item is guaranteed with 7day streak :/

over 650 regular spins now and still no evo item so far... i got 1 upgrade from my 7 day streak though

I guess if you are an average active player (that would be one that reached level 3x by now) you can expect to get 1 item / week.

Most of the time it will be in your 7-day streak bonus, and to me it appears that the chances to get it from daily streaks and regular spins add up to what is missing to a 100% chance on the 7-day streak.

I think I am probably very lucky in this particular aspect but I have 5 evolution items at this moment, got 1 metal coat the first day the second gen came out on a normal spin, another metal coat the second day, a king's rock on my 7th streak and a sun stone the first day streak, today I just got another metal coat.

I haven't got a single 10km egg in like 1 and a half month, so probably the game is sending me a message, you can evolve all you want but no rare stuff from 10k for you hahah :D

I got one from the sole 7-day-spin since the update, 3 others from regular spins.

It seems like it is related to the number of items dropped. Since daily spins drop more items, they are the best chance to get an evolution items. It appears that it is never guaranteed, though.

Just had my 7-day streak bonus, but there was no evolution item....