A simple paper aeroplane became the most dangerous Instructable I've published for some time.
Step 1: Requirements & part 1 of Safety
I made this plane from an aluminium drinks can, using a heavy craft knife, scissors, a piece of scrap timber and a mallet.
There are serious risks during this Make, because the cut edges are very sharp. You may want to consider wearing gardening gloves to protect your hands, and make sure you know where your first aid kit is, because cuts from jagged metal can bleed quite profusely.
Step 2: Cutting
With the sharp knife (in the UK we'd call it a "Stanley" knife, in the US I think it's a carpet knife), cut the top and bottom off the can, then cut vertically with scissors.
Open out the can and press flat with the scrap timber.
I wanted to make a "standard" aeroplane, so I trimmed the can to the same proportions as A-series paper - since the metal was 9cm wide, I trimmed it to about 13cm long.
Step 3: Folding
I folded the plane in the same manner as making a simple paper dart, but it takes a bit of extra effort to make the important sharp creases.
That is, I laid the scrap timber on the bends and smacked it with a mallet.
As you go through the Make, the bends get harder to do neatly. This is mainly because you're folding more metal, but also because the aluminium "work hardens". If you fold and unfold at the same point too often, the metal may split.
A pair of narrow-nosed pliers is useful in folding at the pointed end.