to me...strats only are about 10 minutes long...if...before te rest of your game is adjusting and speed...to gain whatever advantage you can over the enemy..
whether thats higher lvl heros (creeping)...more income (expanding) or countering of units (scouting)
so there isnt a BEST strat persay...sorry to dissapoint

...best thing to do..PLAY A LOT...experience breeds skills...those people you see at the top of the ladders..play A LOT...thats how they get that good