Here is the Parish survival map:
For regular waves I post up in the shop on the left:
Put claymores in the blue area to keep yourself safe from behind and then sit in the red area watching out towards the hovercraft. The enemies will come in along the yellow arrows. A few will enter the shop from behind, but not many and of the ones that do not all of them will come attack you. For some reason they come into the shop, duck behind some cover, and then leave and circle around to the front (red circle).
For juggernaut and helicopter waves I did a loop around the whole map:
This loop passes the air support armory in case you want to buy air strikes, and also the equipment armory if you need anything else. I would always go prone right in front of the equipment armory and get equipment, and in that position the helicopters took a solid 10-15 seconds to get into a position where they could hit me, by which time I was gone.
Parish is a Tier 5 map.
Jugg/helo waves: 4, 9, 14, 19, 24, 28, 32, 36, 40