There isn't a magic formula to increase trichome production, to achieve this you need a combination of different elements. Things like genetics, an optimal growing environment, adequate full-spectrum lights, and good quality nutrients at the right time will result in more resinous buds. There are a number of supplements intended for increasing trichome and terpene production, although they don’t do miracles, they will provide more of the nutrients your plant needs in the last weeks of the flowering stage. Supplements can provide a more specific mix of macro and micronutrients for the final weeks of the flowering stage when the plant is producing more trichomes.