Sword, swinging

Take a plank or another long object and swing it around rapidly as you would with a real blade. This produces a good swooshing sound – and if you layer in some ringing metallic elements (by hitting a metal object), it’s one way of creating a blade-sound. For lighter, thinner weapons, a bamboo stick or another elastic stick could come in handy.
– David Filskov

For source material, check out the Swordfighter Sword Sound Effects library, and recordist David Fienup’s Blades sound effects library.