That's an excellent article on decaling, and a very good reference. I disagree on a few points though:
1) I always start placing decals on the left and move to the right. This is because I'm right handed and tend to put fingers down to stabilize my hand when placing small decals. Inevitably, if I start from the right, I'll put a finger on a decal that is very delicate from the setting solution and ruin it.
2) I never use a hobby knife to cut or trim decals. As a kid I cut through too many decals when the knife slipped slightly. Use scissors, preferably those with a short, curved blade since they allow you to cut curves quicker.
3) Getting the air out from under a decal when it is placed is critical. He uses a brush to push the air out, I use Q-Tips and ROLL them over the decal. I never push until the decal while there is water underneath or it will inevitably move.
4) In the last section dealing with decals on a flat hood one recommendation is to trim close to the graphic and place it on the paint itself. If this is done the hood itself will be flat however the decal will be glossy. I've seen this many times on military aircraft, and it just does not look right. In situations like that I much prefer a flat topcoat.