I hereby vow to improve my fuel efficiency

An article in the Drive section of today's Globe and Mail, a section that I rarely read with much attention, has reminded me of something I once knew, but appear to have forgotten in recent years.
A few years ago now, I read a similar article and vowed to reduce my driving speed in order to improve my fuel efficiency. I kept to speed limits obsessively for a year or more, tried to avoid sharp acceleration, and even planned ahead for the most fuel-efficient way to negotiate hills. This was not exactly "hyper-miling", but it did noticeably improve my fuel efficiency and, for a while at least, it gave me an interesting challenge during the usually humdrum and tedious act of driving.
Unfortunately, it didn't last too long. All it took was a couple of occasions when I was pushed for time and had to put my foot down, and soon I was back to my old inefficient habits. So, this article is a timely one for me.
A vehicle uses over 20% more fuel when driving at 120 km/h on the highway than when driving at the official speed limit of 100 km/h. Yes, the journey at 100 km/h takes 20% longer but, unless there are pressing reasons to the contrary, an extra 12 minutes on an hour's journey is really not enough to get excited about. Even just sticking to the posted speed limits in town is enough to generate substantial fuel savings and, with gas prices back above $1, that can save more money than you might think.
What else can help? Accelerate gently when acceleration is needed; leave more space between you and the car in front (so as to avoid constantly braking and accelerating); allow yourself to speed up on downhill slopes, and slack off the accelerator on the uphills; coast wherever possible (including when slowing to a stop); keep the windows closed and the AC off unless the weather absolutely requires it; and avoid idling while parked. I drive a hybrid anyway (although a 2.5 litre 4-wheel drive hybrid, and so not one of the most efficient cars on the road), so observing these simple rules will have even more impact on my fuel efficiency than they might have with other cars.
The article in question reports fuel savings of 25-30% from the simple observation of these recommendations, and of almost 50% in the case of hybrids. No-one will think any the worse of you for driving like an old duffer (when was the last time you saw someone you knew while driving anyway), and your bank account and the environment will certainly thank you for it.
So, I am renewing my vows. Let's see how long it lasts this time...