You could collect the pollen and store it in freezer until you got some females. Then put just a tiny bit on some lower branch and boom, you have couple dozens of seeds from a single bud and rest of the plant goes on as normal without seeds. If you want sure results, i suggest buying feminised seeds tho. Randomly throwing out pollen will result in random results, buying something professional can result in good results with much higher chances and also you can buy feminised seeds