Craps is my second favorite game. I devised a system to hedge my bets in craps while reducing the variance and making it look like I am betting over $200 a point. I played like that for a few hours and got Harrahs platinum and dropped about $300. That itself is worth the free rooms, plus I must have made about $150 of that back on match play coupons.
If I'm playing a long session of blackjack I'll take a break when the count heads south and I'm getting tired, and bet the minimum + odds on the pass or dont pass bar in craps (while rated of course) for a few points. It's low cost cover and a nice break from counting cards. When the pit boss is looking at my bets to determine my rating, I'll bet $25 on the dont and place the 5-9 for $10 each so he enters a higher average bet. Then I take down my place bets after the pit boss leaves. The best part about craps is that I can get rated by just standing at a crowded table without betting.
Another game I like is Texas Hold Em Bonus. I play on a crowded table and try to see as many player hole cards as I can before deciding to raise or fold before the flop. While it may not turn into a player edge, one or two good folds per hour based on the additional information would reduce the house edge. Again, I bet 2x or 3x the minimum on the first hand while the pit boss is looking to get rated higher and then drop to the minimum and even sit out a few hands. If the same pit boss from the blackjack table is watching, they would notice that I bet erratically and sit out on a -ev game too.
3 card poker isn't my favorite since I always seem to lose quickly on that game. I never bet the pair plus.