My wife dries a few flowers and herbs. She puts a few stems together, secures them with a rubber band and hangs them upside down on our enclosed porch. If seeds fall from them, she collects them and uses them the following year.
I live in the south, so our greens and things like that go to seed when it gets real hot. I just hang them upside down to dry in the greenhouse and then collect the seeds. I've collected petals from the rose bushes along with lemon zest for potpourri. Just collect and bag. Make sure they're good and dry.
I went through and put all of mine in brown paper bags and tied them with an elastic. I am hoping for the best, I have never done this kind of thing before.
I have tried it many times but have never succeeded. Usually they just get too dry and brittle and break apart. There is not ever any smell left either. I don't know what I am doing wrong.
I think for the most part is is trial and error and when you get it it will be as if you had been doing it that way the whole time. Once you tweak your way it will be the only way you will do it.
I have found quite a bit of success with tying 4 - 5 stems together with string, and then putting them upside down in a paper bag. I've punched a hole in the bag first. The main thing I find is that I have had to find a warn airy room to hang them. When I used to hang them in the pantry, where we keep the door closed, I had problems with mold. So now they get hung in the kitchen/dinning room. It is one big room in our house and I keep them away from the windows and doors near the middle of the house.