What are your tricks to good MPG in your "other" c

I am just curious... I am somewhat of the MPG freak on my current ride (2002 Nissan Altima 2.5, manual 5 speed). I drive 53 miles a day on my regular commute to and from work. It's about 40% city : 60% highway. The Prius (on order) will replace my wife's car though, I just paid off my Alti.

Anyway, I am getting 29-30 MPG in my Alti tank after tank (during my commute), this is measured at the pump, not from trip computer. I always refuel at the same station and never top off. I drive until the light comes on, at which point I can squeeze a little over 16 gallons in.

Few things that made a noticable difference for my MPG:

1. Using non-alcohol STP fuel injector cleaner every oil change (7K miles for me) - first time I used it (after 20K miles) - my MPG went up by 2MPG, now its constant since I use it periodically.

2. Using Mobil 1 Synthetic 5W-30 oil - it gives me 30-40 miles/tank difference. I have confirmed that twice - after original synthetic oil change and once when the dealer did a recall and changed my oil without asking me - my MPG went down. Later I found they put in dino juice and not Synthetic. When I switched back - my MPG went back up Again, I make it work 7000 miles between changes.

3. Using Shell gas (cheapest stuff, per the manual). This is strange, but I tested every single brand from home to work for few tanks. Shell always gives me about 30 miles more per tank?? But hey - whatever it likes...

I drive with 33 PSI tires (manufacturer's recommendation is 31, but I have tires that are a little wider than stock).

I tend to shift at 3K RPM. When at hwy, I cruise at about 3K too (75 MPH). I don't drive like a granny, but I don't stomp on it all the time either (OK, sometimes I redline it but not often )

MPG game is just that - a game for me. Wonder what do you guys do on your cars? Hybrids are a different category, that's understood.