Hey Mate, there are heaps of things you can do to make you plane lighter. Here are some ideas:
Carbon Wing Tube
Carbon Elevator Stab Tube
Carbon Fiber Main Landing Gear
Carbon Fiber Tail Wheel
Lightened backplate on the spinner / or get a carbon one
Li-Ion Batterys all around
Smaller tank, try a 20oz
Light weight wheels and axles help allot. Try Karvan Wheels with PSP Manufacturing Titanium Axles
I dont know if a CF Prop is lighter than a woody? help me out here guys. I know PT Carbon is light
Take out any unessacary items that are not needed inside the plane.

I have worked out , i can save anywhere inbetween 400-500 grams in my upcoming plane. Thats HALF A KG.