as far a resin go`s(gland heads on storked trichomes) keep the air as dry as pos idealy humidity around 50% or lower this can be controled quite easyly and cheeply with a small dehumidifier. Apart from good light this is the only other facter you can easy control for better resin production.
I don`t think the size of your bud is a problem as long as they have adaquet light they will reach potencial.
My good buds(flowering cinamon and grapefruit under 400w hps, almost done) are about an inch long and nice and fat.
but the i do`nt know the size of your thumb.