While installing my Ikea kitchen, I figured out a way to add a toekick drawer without any special equipment. This was pretty easy because I did it before installing the cabinets, but it's theoretically possible to retrofit an existing cabinet. I found that a drawer designed for a 30-inch cabinet fits perfectly under a 36-inch cabinets with toekick boards installed onto the feet underneath. I haven't tried it, but I suspect that a 24-inch drawer would fit under a 30-inch cabinet and a 18-inch drawer would fit under a 24-in cabinet.
Step 1: The View Underneath
I wish I'd taken pictures of this during installation, but hopefully this will be clear. I used a 36-inch cabinet with 4 legs on the outside. Then I installed the toekick boards on the side legs to support the drawer rails. I used a scrap piece of 2x2 on the inside corner to keep it solidly in place. You'll have to drill pilot holes in the board in order to install the drawer rails, and check really carefully to make sure you're getting the locations right.
Step 2: The View From Outside
Another view of the rails and support
Step 3: The Finished Product
Voila! Extra storage space for very little. It's not a huge drawer, but it's good for holding big things like cake pans. The front is more toekick board with the iron-on veneer on top. The front attaches with the same hardware that comes with the drawer for regular drawer fronts, but you'll have to drill pilot holes to install it. It's really tricky getting the measurements right, so triple check everything before drilling.