In addition to the starting seeds using a Ghetto Greenhouse you can also start your seeds using the "Baggie Method." Starting from seed using the Baggie Method is a simpler and perhaps cheaper alternative to making your own mini-greenhouses. You won't need soil or containers to start with, what you will need is a plastic sandwich bag (reusable) and some paper towels. From experience I'd recommend using the thickest paper towel you can afford, I suppose you could also use newsprint but only the black and white section of your newspaper. Instead of throwing away those paper towels you may use to dry your hands- set them aside and use them with this method.
This method is really simple; take your paper towel and fold it so that it will fit inside your sandwich bag and moisten it (if it's dry) either with a little running water or a spray bottle. You don't want the paper towel to be soaking wet only nice and moist. Then place your seed(s) inside the paper towel and place inside your sandwich bag and set it somewhere warm away from direct sunlight.
After a few days you should have results similar to the image above. I used the baggie method to start seeds from an orange I ate because I have a hard time tossing any seeds I come across. I just followed the simple steps and I set it near a heating vent. In the winter I use the heating vent in my bedroom similar to how one would use a propagation mat because if the heats running I might as well use it to grow something.
While I use this method to start a lot of "tropical" seeds I have used it to start seeds from things like; Hollyhocks, Morning Glories, Alliums, Hibiscus Syriacus, Cacti to name a few.
Back in elementary school we used a method just like this to start seeds for a class but we used an empty pickle jar, in place of the sandwich bag, that we set atop the refrigerator. I've recently tried germinating seeds on top of the fridge and I have very poor results. I think the reason for my poor results is the energy efficient advancements in home appliances, the top of the fridge just didn't get as warm as the old one used to. Oh well.
Check the link on the right hand side of this blog for the best seed germination data base I have ever come across.