I know BAB gives additional attacks, but i was wondering if its possible to stack the bonuses for these bonus attacks towards one focused hit, for example taking a full attack action with +6/+1 BAB and using it for only one attack with +7 BAB for the roll. Or +11/+6/+1 to get one +18 attack. It gets frustrating trying multiple attacks that fail harder each time against a monster. Wondering if my character could just take its time during a full attack action and just get one guaranteed hit on its turn.
If you are having a tough time hitting with your iterative attacks, you could try tripping with the first attack. All attacks after that will have a +4 to hit.
If an enemy is challenging enough that you miss on your first attack with a good roll (13+), then either your GM has it out for you and wants you dead, or intends for the party to use some teamwork to pull through.
Weapon focus, greater weapon focus, flanking, and enhancement bonuses on the weapon. Also class features such as favored enemy, weapon training, arcane pool. These are the ways you pump your to-hit chances up.