Since the three step nearby issue is still around (some say it is deliberate), I have been using a few suggestions from programmers and utilizing "bots" in order to scan my local town and the larger city I work in, in order to a) find the spawn points and b) find what spawns there

With only a few days data, I have already been able to find a few nests where one Pokemon seem to exclusive live, along with other areas that have a higher number of some of the less common items.

It all still comes down to luck and timing however as to what will spawn when you visit the area at the correct time. Due to needing to collect multiples in order to get candies and evolve, along with how a Pokemon will get stronger as you level up I can already see multiple visits in my future to these locations.

All of this is of course against the terms of service, but it does actually make the game fun, otherwise my only hope of getting some items is via hatching eggs.