Don't defoliate...........all those leaves you removed were providing most of the energy your plant needed to grow its biggest buds!
Quite simply,
Less leaves = less energy being made = less flower growth.
Afer this, genetics, lighting and correct feeding are the three main limiting factors for bud size.
A plant can not grow buds bigger than its genetic blueprint, but it can certainly grow smaller buds with incorrect feeding and poor lighting.
It is all about providing the best possible environment so that a plant can express its genetic potential to the maximum.
There are no magic products that can turn a plant from average flowers to monster flowers, regardless of what the nutrient companies try to get you to buy.
However, reducing a plants ability to make energy (defoliation) will certainly decrease flower potential.
If you want more buds, grow photoperiod fems and not autos, that way you can control when flowering occurs and only once you are satisfied with the plants' size, rather than autos which will flower at a pre-determined age, no matter the size.