Go solo and start at a bar right around the corner from the field. Pick a spot with a decent TV that’s locked into the game-—I usually go to Huberts across the street from the Metrodome in ¿Minneapolis. Watch the first inning on TV.
When the first inning’s over, cross the street and tell the scalpers you want one ticket. Offer $15. They get stuck with ¿singles, and the guy’s probably heading home, so he'll take $15 over nothing—and you’ll probably get right on the field.
Don’t eat. There’s nothing at the stadium you can’t get better or cheaper when you leave, especially if you’re watching the Mets or the Yankees. Exception: the garlic fries at AT&T Park in San Francisco, where the Giants play.
Keep score. There are so many people-watching opportunities, but you’d be surprised how much keeping score helps you focus and get more out of it. And remember, they usually stop serving beer after the seventh inning, so load up.