Find a bar that's playing the game and has machines.
Slow play the machines.
Drink a lot.
You'll expect to lose money gambling, obviously, but it's cheaper than paying for drinks. Your mileage may very.
I don't know what kind of action you'd put down on the game, but ask for drink tickets if you don't get any, or if you do -- ask for more. Try to find a friendly lookin' bet writer.
Probably frowned upon, but you can probably just ask other people for their tickets. Obviously don't solicit them out of the blue. But maybe get in line behind a guy who looks like he's got some money. Ask him what he's betting on, agree with him, and perhaps gently bring up the tickets thing, like "ya know how I can get extra drink tickets? I don't bet much (as much as you), just want to have a few during the game. " might be enough for him to just give you some of his tickets or all of them. Also, probably wouldn't be tough to buy the tickets for $1-2 from random people who're leaving the booth.
You can probably even find some just laying around or in a trashcan if you're into that sorta thing. Trashcans are probably cleaner in a book than other places, since it should mostly just be empty bottles, losing tickets, parlay cards, futures sheets, etc. But you probably don't want to be seen digging through the trash.
I don't know what the money line or points lines are for any of the games. But baseball tends to have close ML's with a 10 cent difference between them. So if you can find something like -140 and +130, bet $140 on one side and $100 on the other. The favorite is more likely to win, and you break even. If the underdog wins, then you lose $10. But you have $240 in action. This is a guarantee-can't-win scenario, but your expected loss is $4.27 combined, and at most you'll lose $10. You can probably get more value than $10 in drinks (if you'd otherwise pay cash for them) anyway. Better to bet more money, depending on how many drinks and stuff you want. Do it for $500 and $700. Expected loss is about $21 and worst case you lose $50.
Of course you'd want to stagger your bets and/or have someone else put in the other side with a different writer.
Is it worth it? I don't know. Maybe. For some, no. For others, probably.
"should of played 'Go Fish' today ya peasant" -typoontrav