Without magnifiers

Well if you can't get a hold of a microscope, you can always go for the time recommended by the breeder. You can also try and look at the hairs. In most cases they will color and start to curl in the end of flowering. Though you should be careful not to touch the flowers since this will also cause them to color and curl 😉 In general it's also recommendable to when you think it's ready for harvest, wait another week or two. All these methods will help, but in the end a microscope will make your "harvesting at the right time" much easier 😊