Place 1 Nether Wart in a Brewing Stand with Water Bottles to make Awkward Potion
Add 1 Sugar to the Awkward Potion in the Brewing Stand
Collect the Swiftness Potion
Optional: add Redstone Dust to extend the duration
Optional: add Glowstone Dust to make a stronger Swiftness Potion
Optional: add Gunpowder to turn it into a Splash Potion of Swiftness
Optional: add Dragon’s Breath to turn it into a Lingering Potion of Swiftness