If you're interested in starting a new tree from seeds, like a citrus tree or an apple tree, you can always dig a nice hole, drop the seeds in, and hope for good fortune, or you can get creative with a seed starter to help the germination process take hold. This method uses a few old sandwich bags and some napkins to get the seeds started quickly and easily so you can plant them and nurture them later.
Just grab a few plastic sandwich bags (used ones are fine, just save a few from your brown bag lunches) and grab some napkins. Instructables user MrBrownThumb explains that you layer the seeds in between a napkin and lightly moisten it with a spray bottle (just a little, you don't want the seeds to mold.) Soak the seeds overnight, then fold up the napkin, put it in the bag, and leave it next to a warm spot like a heater or a sun-drenched window. Check on them every few days, and when they start to germinate, let them grow until they're the right size for a small pot.
We've discussed a few seed starter methods, including using a citrus peel or newspaper seedling pots, but this method lets you reuse old plastic bags to get the job done. Granted, you don't get to use the starter as a decomposable pot the way you can with the citrus peel or newspaper pot, but for large seeds that need more time and attention to germinate before you drop them into a pot full of soil, this technique may be helpful.
Seed Starting with the "Baggie Method." | Instructables