A little more...
I agree with the above that 2-1 coupon is the most valuable & speed is key. A few more things to consider along those lines:
Use the coupon during a slow time, probably graveyard would be best, to avoid table crowding and therefore maximize hands per hour. During crowded times, even if you start at an empty table, others will likely join before your hour is up which slows the game or you waste time moving.
Watch the dealer before joining for their speed. Some dealers are just way too slow. If the dealer is slow, find another table, wait until shift change, or wait until the next day. To illustrate this point and also the value of the coupon, with a fast dealer (and assuming the player can play fast), it is possible to get around 400 hands/hr heads up. This should yield around 19 naturals on average during an hour, so the extra 1/2 unit payoff on $25 bets is worth about $237.50 (nice coupon!). Now say we have a slow dealer or someone else joins and we only get 150 hands in that hour. This would only yield us around 7 naturals, or only $87.50 for the coupon, which is $150 less than the 1st example.
If by chance the CSM game is not available or crowded (usually it is the least crowded though) and you don't want to wait on it, then a shoe game is much faster than pitch games as a 2nd choice. Don't sit through a hand shuffle though. Find one with a shuffle machine or be looking for another table with a near freshly shuffled shoe.