I've been looking for a consistent FM 2013 tactic since I bought the game, tried loads of different ones with no joy, for example, winning 4-0 at half time, then losing 7-4 at full time (really frustrating!)
I stumbled across this tactic which claimed to be the best, and so far for me it is!
Football Manager 2013 best tactic, 4-5-1 with fluid attacking football
I take no credit for this tactic but I've had awesome results with it, I'm currently Cardiff in the premiership, and since using this tactic, ive played 34 games, winning 26, drawing 3 and losing 5 (most losses due to a terrible run of injuries to my defence).
If you're looking for consistency and an attacking tactic that creates loads of chances, this is it!