One of the tricks Chrysler used when the Mobile gas economy runs were a big thing was to get into top gear as quickly as practical.
Overinflating the tires by maybe 2 - 3 PSI helps.
Accelerate gently and try to adjust your speed to minimize time sitting at redlights. = Slow down a little when the light ahead is red so you get there when it goes green.
Buy gas in the morning when it is cooler. Warm gas expands, so you don't get as much energy per gallon when you fill up late in the day.
If you have bags on your bike, leave them home unless you absolutely need them. Extra drag and weight costs gas.
If you need to, go on a diet. (See above)
Keep your jacket closed up to reduce drag. If it is a loose fit, consider getting one that fits tighter.
You might get a small power and economy increase if you take the rubber tubes (snorkles) out of the airbox.
