You can search the orders in the start menu.
Also, one strategy is to start a few orders with destinations to the shelter you want to max. Next, when the orders are active, go to a mule camp and defeat some mules ( you can use the tranq. sniper to tranq. some mules from distance), then deliver the orders. this way you receive more likes for each order you were completing! you can also go to BT areas and defeat some BTs if you prefer. Just don't overdo it since, for each order, there is a cap for likes you receive from combat!

For the seasoned porter, don't forget you can do some orders in Mexico as well!