rec. premium spark plugs(e3). examine ignition coils for damage to boots(charring). never seize. fresh air filter(rec. upgrade to high air flow design such as K&N). more air mean more power.
rec. oil stabilizer with oil change. this will recondition seals and cylinders(improves compression).
be sure to coat threading on new spark plugs with never seize prior to install. if any coil boots show signs of charring than replace. if you want to go all out than rec. upgrade ignition coils to performance grade. accel super coils are good and more cost effective than OEM replacements(up to 40%).
rec. fuel system clean. ethanol treatment to 1 tank of premium.