On occasion, the difference between lugging hefty stringers and going home empty handed is minute. Anyone who's ever wet a line has either been handed their lunch by a buddy or vice versa fishing the "exact" same bait. While it sounds impossible, closer evaluation of equipment, lure and presentation often reveal subtle, yet significant differences.
Case in point: Two buddies routinely fish inshore for trout and redfish. Without exception, the one friend wallops the other buddy time-and-time again. Throwing the same bait, wading side-by-side. Their bait of choice is a weightless, imitation shrimp. The difference? One throws a baitcasting rig, the other, spinning gear.
According to the successful buddy (who has yet to tell his friend this), the spinning gear makes the shrimp fall with a slight list to one side due to line twist (he figured this out years before). So, the fish favor his more natural looking shrimp.
When faced with a similar situation, take time out to evaluate every plausible difference between what you're doing and the guy (or gal) who’s whacking them. Check line weight and type (fluorocarbon versus mono), rod length, rod action, reel type, lure (weight, color, size, scent, no scent, rigging), casting distance and angle, retrieve speed, leader length, means of attachment (type of knot), cadence, pause times, retrieve distance (how far you work the bait back before recasting), rod height (position), line management, and so on and so forth.
Rarely –– and I do mean rarely –– will you find you're both doing "exactly" the same thing.