Any tips on getting strange coins? Best planets to go to, enemies to kill etc?
Imo the best way to get strange coins is to find a leprechaun and start beating the shit out of it until it gives you it's pot of strange coins.
There is the weekly mission that well give you some guarenteed. You could also try strike playlist. I was playing for an hour and saw 2 drop directly (for other players), and the higher end errands you receive can also give strange coins if you are lucky. On that note, I have also seen then drop at the end of crucibal matches, but you generally get more engrams during a strike.