All the popular spots like if you are playing Erangel you’ll always find great loot in Military Base(personally that is my favourite) you are bound to find a sniper or a Flare gun or maybe two. But you wont be the only one after that loot so be careful. Another great place for loot is Pochinki (if you are lucky you’ll find the perfect loot on entering the first house you’ll see). Then comes Georgepool (crates). Well that is the most dangerous places to get down and its kind of hard to defend. But I suggest get down at Georgepool City. Really less number of people get down there and there are ample houses to loot and get what you want. Other places that have proper loot are Yasnaya and the waterlogged houses of Rozhok(now this place is not visited by a lot of people but has good loot for required for survivng the first intense 15 minutes.
If you are playing Sanhok. Literally get down at any small patch of houses or any of the places in the map. You’ll always find an AKM or a M416 or QBZ. Loot is really evenly spread in this map.
As for Miramar I havent tried all of the places myself. Whenever I play i get down at Haciendo Del Petron or Los Leones or Sahmee.