Oh yea forgot trying to get the in the smaller maps also
"Downtown" by "a" if you were playing conquest is a good place to put one. Place it at the intersection.
Place one on "dust bowl" on any rooftop overlooking the action on the map. Pull up the big map and watch the flow of action. Equip the grappling hook, find your spot and place your coin. Same map, place one by the diner in the parking lot. There's usually action there.
On "the block" I'm 100% on this. Only tried once cuz it was my 5 of 5. Place one in the street on the left side of the map if you spawn from the convenience store. Also place one on the roof of the semi truck blocking the road on the right hand side of the map. I got a coin doing this after I hopped in a match with less than 100 tickets left.
Remember to line the coins up so they have a clear view of the action. The fewer blind spots the better.