Step 1: Intro. Show All Items. This instructable will show you how to make your own ferrofluid. A ferrofluid is a fluid with magnetic particles in it, and if the fluid is exposed to a magnetic field, all the magnetic particles will align with the field lines, and making the fluid much more dense. There's a lot of cool things you can do with this fluid. Enjoy!!! Â« Previous Next Â» View All Steps Download.