Short shifting is fine. But I'd say those upper shift points are too late
depending on what you're doing at the moment. Especially if you're just cruising at very light load. I'll often grab 5th @ 25-30 mph depending on what's going on (maintaining speed, light load). Highest gear you can use without lugging. If you need power to accelerate, downshift. That's what makes driving a manual more interesting.
Are you neutral coasting to as many stops/turns as you can? (Driving Without Brakes)?
I'm sure you've looked through our list of driving techniqes -
100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com
I'd also consider dropping your highway cruising speed, to say, 55 mph. See:
http://ecomodder.com/forum/showthrea...you-15182.html