You have the "soft" way, you have the "hard" way.
Soft : you work with paint and precise tools to make you saber LOOK weathered. But he will just be worked to looks like.
Hard : let it fall some times on the ground, make some scratch yourself. USE IT ! Mine has already hit the ground while practicing a couple of times and each scratch added is a story.
For other effects, you can use some enamel paint. I can give you a tip I earned for an other hobby of mines : Figs (WH 40K mostly - Orks and Tau
)
Take some foam (blisters' foam) and some paper towel. Put some paint on the foam and dry the excess of paint with the paper. Then test the effect on some paper : you will have a doted pattern that looks like dots of rust or scratches.
Then, for scratches use some silver paint (basically, a lighter color that the saber's main color) and for the rust some brown mixed with metal.
One of my favorit aspects with my vehicles is :
- Step one : paint it in the "brand new" color, what it would have looked if it was just painted.
- Step two : tap the foam with brown to make some "old scratches + dust" effect
- Step three : tap the foam with dark-metallic paint to make "quite old scratches" effect, just make it lighter that the precedent
- Step four : tap the foam with silver-metallic paint to make "brand new scratches" effect, lighter than the precedent.
For the sabers, I think you could use the same method
