What should use to make this batch stronger than last

Strong lighting and quality genetics is the only answer for killer buds, not any sort of particular nutrients. Don't defoliate......... more leaves = more energy being made = more buds.

There's no magic recipe or formula you can buy, make sure you've got a good light, extractor and general environment for em. If you know something in your system needs or should be upgraded do that before spending daft money of nutrients and boosters

there is no technique or nutrient (not for consumable plants anyway) that will overdrive a plants genetically carried potency potential. to reach that potential you gotta grow them at perfect health.