Tipis are one of the easier scratch-build projects possible. We used to do them as an arts and crafts project in elementary school!
Materials needed:
Sticks - mostly the same length, with two that are slightly longer (these will be for the smoke flaps)
A half disk of paper or cloth, cut according to the tipi pattern (try one of these for ideas:
http://www.manataka.org/page193.html http://education.boisestate.edu/compass/Idahohistory/Chapter%203/Tipi-cover-sm.gif )
Material for the base. In school we used corrugated cardboard, but MDF would probably be more durable.
Take the bundle of sticks, of similar length, and tie them together at one end. Stand them up so they form a cone. Either glue them to your base, or drill holes in the base and secure the poles in the holes.
Wrap the cloth or paper around the tent poles. Real tipis are pinned along the seam, but glueing the seam should be fine.
Paint some pictoglyphs on the outside and you are finished!
Another set of instructions can be found here:
http://education.boisestate.edu/compass/Idahohistory/Chapter%203/Mod2Ch3kids.htmHope that helps,
Will