I've seen some great tips here and want to add a few.
I've managed to average over 60MPG lifetime for my '04HCH and probably the biggest contributors are:

#1 Slower speed.
I'm not talking about the granny holding up traffic here.
It takes a while to develop a skill to know when you can safely and courtiously slow down and judge traffic (or the lack of)

There is also the matter of type of road you are traveling.
For example I could take the 55,65,70MPH freeway all the way home on my 50 mile ride. If I choose to do so I usually get around 55MPG.
-But- If I exit 1/2 way home and take the side roads/parallel highway with 45MPH limit I can milk it much higher, well into the 60's MPG.

The parallel highway increases my arrival time by 4-6 minutes depending on how stop lights play out. For me the calmer ride and increased savings is worth the few minutes. It takes me an hour to go those 50 miles so my average is about 50MPH.

#2 If you have a FCD then learn how to use it
My own (and most people's) commute route changes very little from day to day. The road almost never changes. Most folks just blindly gas it over the little dips, hills but we can use those to our advantage.
Using your FCD you can learn exactly how much fuel to feed for every section of your commute and maximize efficiency.

#4 My next biggest tip is controversial. It's using your car's Neutral position or key off. This is illegal in some states and can be dangerous in some circumstances. If you aren't comfortable with this then don't do it.
But there are some circumstances when coasting in N can be done safely, and it quickly gains MPG. Engine off provides rapid MPG gain but if used improperly can cause a crash.

Wintertime I coast in N probably 7-10 miles over my 50 mile trip. I don't key off becuase of possible radiator strain of constant extreme heating/cooling.
Summer time I usually replace coasting in N with engine off but with extreme caution under certain conditions.

#5 Higher tire pressure
My tires are set to maximum cold pressure rating as stamped on the tire. That's 51PSI in my case. They are hard. They are efficient.
My last set were the OEM Dunlops which wore evenly and were replaced at 88,000 miles. They were rotated every 10,000 miles and alignment done every 15,000. I got the same model: Dunlop SP20FE's.

#6 Careful warm-up
Your engine is a comparative fuel pig when warming up. You can assist your engine a faster warm up by setting your cabin heat to cold for the 1st 10 minutes or so, and also keep engine load as light as possible. There are also other things you can consider.
For example, instead of jumping right onto that freeway with a warming engine, perhaps you can drive a parallel road to the next entrance, allowing the engine to heat up better before the demands of a freeway.

#7 Air conditioning and Defrost
If you keep the blower control to off and the air director to defrost you will have a constant flow of air to keep your windshield clear of frost. If you do need to clear it, you can briefly rotate the blower control to high. This will start the compressor and rapidly clear your windows. Once the windows are clear turn the blower back off for economy.

Instead of using climate control or just letting the AC always run, consider manually cycling the AC button as needed:
But only switch it on while decellerating or coasting. Never allow the AC to run while accelerating or climbing hills for maximum economy.

#8 Potential parking
Back in and face-out, so that you pull out without having to stop, reverse and go again.

#9 Allow your regen to become a larger part of your braking force. That is coast further and try to apply your normal breaks only when you've already slowed most of the way down.

Those are my own top tips based on a HCH-1, but most can be applied to what ever other vehcile you drive, to go along with the other good tips were posted here in this thread such as keeping momentum, accelerating in your engine power curve (FCD helps there too) timing lights etc.


-Steve

 

These are good tips. In January, I purchased my civic hybrid and after 3 months, I made my wife give up her tahoe for the highlander hybrid.

Until last week I was averaging about 39-40mpg in my civic, until I discovered that coasting increases fuel economy dramatically. I am now averaging between 46-50, and am now on a mission to break 50 consistantly. I have discovered I hate the overpasses on the interstates, as I have to touch the accelerator.

Also, I turned of the AC this week, not sure if this is helping my mileage or not since I introduced two changes in one week. Does this help, or am I suffering for no reason?

Thanks...

 

A/C certainly uses energy in measurable quantities, but there are valid reasons for using it moderately in a hybrid. At least in a Prius, the battery is cooled by air drawn from the cabin. If that air is too warm and the battery gets too hot then the computers cut back on charge/discharge rates, reducing the benefits of the hybrid system. Can't imagine why it would be different in a Civic.

 

The first of all when you are on the road, avoid having to stop and start your car repeatedly. Maintain your average speed definitely have a positive impact on your gas consumption. Maintain your air filter and keep a safe distance from the vehicle in front of you it will also have a significant impact on life engine and performance.