which pokemap do you use?

Silph Road atlas.

Yes, for nests. But also:

https://gymhuntr.com/

For gyms.

Third party Pokemon scanners that rely on "bots" have been heavily cracked down on by Niantic. They have basically decided not to offer a real-time "hunting" type game experience at this time - hopefully someday they will introduce something that they consider safe and profitable.

I have enjoyed visiting nests that are identified on the Silph Road Nest Atlas, and I've reported a few of them that I have discovered.

For those few species that don't really have nests, like Larvitar and Dratini, I guess we're supposed to rely on eggs now.

I'd tell you but then I'd have to kill you...

(ok ok fine. most that are still around require a lot of work. Hunting down the apk files, making multiples PTC accounts, buying an API key from overseas, and then careful use. If you want to just go to a website and look at an area certain websites like pokesear.ch still work, but it's a very small area and you have to wait between scans. If you're in a handful of major cities, they have maps like nycpokemap.com which are unbelievably helpful)