This 330uf 25v Low ESR Capacitor, made by Panasonic, is great for reducing the noise in your setups. Ideal on setups which have little on-board filtering (like a setup using a 4 in 1 ESC, but great on any setup), this Panasonic Capacitor will add a ton of filtering might to your setup. The result will be better video, less noise introduced to your Flight Controller, and a setup which overall operates better than a setup without a capacitor.
Solder the capacitor direct to your ESCs positive and negative leads. You will need one capacitor for each ESC. Ensure positive and negative are correct.
Link to Oscar Liang Article about capacitors.