Keep a few things in mind when cutting your own arrows:
You have to be quick with your cuts. Letting the end of the arrows get too hot can cause degradation of the resin, weakening the tip of the shaft, which can cause catastrophic failure.
Use low temp ferrul-tite on carbon arrows. That will let you remove the ferrules in the future should you ever need to do so (slide a drill bit into the nock end of the arrow, replace the nock, hold the shaft by the nock, gently warm the tip of the arrow over a stove burner, not flame, gets too hot, point the arrow upward, and swing it sharply downward a few times). Heat your ferrules, apply the ferrul-tite, and twist slowly as you insert it into the shaft. Overtwisting can make the ferrule adhesive slip.
Bend a piece of wire sharply (coat hanger works great) and snip it with side-cutters to produce an L-shaped scoring tool. Score the inside of the shaft slightly by pressing the sharp point of the L wire on the interior while rotating the shaft for the length of the ferrule to allow the ferrule adhesive to better grip the inside of the shaft.