I got this parlay goin on, with 2 legs left, any advice to guarantee good return?

Parlay (6 Teams) 11/06/11 00:01 ET bet 7.50 to win 356.14 Result: Pending Bears(Chicago)
Eagles(Philadelphia) 11/07/11(20:40 ET)
Eagles(Philadelphia) -7.5 Browns(Cleveland) 12
Texans(Houston) 30 11/06/11(13:05 ET)
Texans(Houston) -10.5 Dolphins(Miami) 31
Chiefs(KansasCity) 3 11/06/11(13:05 ET)
Dolphins(Miami) +4 Falcons(Atlanta) 31
Colts(Indianapolis) 7 11/06/11(13:05 ET)
Falcons(Atlanta) -7 (-105) Ravens(Baltimore)
Steelers(Pittsburgh) 11/06/11(20:35 ET)
Ravens(Baltimore) +3.5 (-115) Seahawks(Seattle) 13
Cowboys(Dallas) 23 11/06/11(13:05 ET)
Seahawks(Seattle) +11