Coming in, my approach was to be aggressive at filling the scarcity positions around the diamond (SS, 2B, C), and wait on drafting a 1B/OF types since they tend to be more abundant.
Of course, when Willie McCovey came my way in Round 5, I sort of abandoned that strategy. Instead, I asked myself, "Is this player good enough (or a good enough value) that no matter who comes over the transom in future rounds, I'll still be satisfied with my guy?" If the answer was yes, I made the pick without hesitation.
This only bit me once, when Joey Votto fell into my lap two rounds after I'd taken McCovey. Wished I could have gone back and grabbed Marichal or Perry (or Bill Henry, for that matter), since McCovey's Giants team had way better secondary options than Votto's Reds team. But I remind myself that the perfect is the enemy of the good.