full tune up. upgrade to premium plugs(e3). examine ignition coils(replace if damaged). rec. performance grade coils as replacement(accel's more cost effective than OEM replacement) as they offer more conductivity(bigger spark, better burn, more power).
rec. upgrade conv. air filter to high air flow design. more air, better burn.
rec. oil stabilizer treatment next oil change. this will recondition seals and cylinders(improve compression).
rec. fuel system clean. ethanol treatment to 1 tank premium fuel. ethanol blend in fuel causes build up fuel system, combustion chambers, exhaust system and causes increased wear to spark plugs.
make habit of checking tire pressure. insufficient or unbalanced tire pressure can kill on road momentum which kills fuel economy. be mindful of your suspension for the same reason as tire pressure. watch for soft shocks, wheel alignment, worn suspension or steering components. repacking wheel bearings will help also.
have brakes inspected regularly. if they don't release properly then this also kills momentum.
most of this stuff you can do yourself(save money on shop charges). you may not get big gains emediately from this approach but over time it will help.