We previously wrote about a Kickstarter for a tool that turned any food into a colorful bowl of beads. It turns out, you don't need a contraption like that to create caviar-like foods at home—all that's required are three ingredients and some basic kitchen equipment.
Instructables user Holly Mann wrote a detailed tutorial on how to orb-ify any liquid you want. To get started, you need agar-agar (or gelatin), oil, and the liquid of your choice. While you can use any liquid you like, Mann recommends something thin like juice because thicker liquids are less likely to hold a perfectly spherical shape.
The first step is to fill a tall glass with vegetable oil and put it in the freezer. While it chills, whisk the juice and agar-agar in a saucepan until the mixture boils. Once the vegetable oil is cold, take a dropper or syringe and squeeze out globules of the hot mixture into the cold oil. This will create bead shapes that will sink to the bottom of the glass. Next just strain the glass, and viola! You're now a molecular gastronomist.
You can read the detailed instructions here. Some trial and error might be involved to get the shape just right (most notably, make sure the oil is cold enough and your liquid of choice is hot enough), and if it still doesn't work, you can always get a caviar maker.