I know my win pct so I know what lines I'm willing to play (higher ROI the more likely the play). I don't really follow the money but use the books to see about where the line will finish. If its currently a play but moving other way, I'll wait to see the closing line and then make a decision. Generally, at least with football, you want to be opposite of the money, at least the primetime games like you said.
Good luck!