In just ten easy steps! And frankly that's being fairly generous. I read a lot of these things when I was a kid, and I think I could do it in seven.

1. Read Lord of the Rings.
2. Read the latest edition of the Dungeons & Dragons manual. Create your characters as described.
3. Change the Ring to something similiar: magic sword, magic boots, magic staff, magic spell, magic book, the dreaded teapot of doom, etc.
4. Replace all instances of the word hobbit with something else: halfling, kender, gnome, elf, half-elf, peasant, or what-have-you.
5. Draw a map that looks kind of like Middle Earth but not so much like Middle Earth, if you know what I mean. Name your locations with vaguely Anglo-Saxony sounding words and sprinkle throughout.
6. Cut out bits as appropriate to your desired length. Then move what's left around.
7. Come up with one or two twists on the same old thing. Throw these in someplace inconspicuous.

And, you're done! Enjoy!