If nothing seems to stand out as strong enough to play you may be better off just betting nothing. Action for the sake of action usually leads to bad bets.
Besides, there may be good opportunities that present themselves at halftime for a 2H play.
I would say stick with your single straight bet and leave it alone. The more you throw out on the board the more your chance go down to win. Play your straight bet and have fun watching the game with just one play you need to focus on.