Only plants can make essential oils. These oils are the 'essence' of the plant, hence the name. The best we humans can do is to extract those oils, and to do this, we need vast amounts of plant material, and horribly expensive crushing and distilling equipment to do it with.

I've only tried it with lavender, just for a giggle. Cram as much lavender into a saucepan as you can, and cover with water. Cover the pan, and simmer gently. After a while, when you lift the lid, you'll see some blobs of oil floating on top of the water. Syphon them off with an eye-dropper and bottle. That is the essential oil, but it will unavoidably be contaminated with a little water, so it won't store as long as the commercial essential oils. If you get a teaspoonful, you'll be doing nicely. The oil will evaporate quite quickly with the heat of the water.

For the amount you get and the power to 'cook' it, you might as well pay for the commercial stuff. But to satisfy your curiosity, try my way, with different herbs of choice. It does make the house smell nice while you're mucking around with it!

Thanks! I was thinking I'd start with lavender also. I need to dead head them.

I was reading up on this and found that espresso makers are just little distillers. But you have to use the kind that steam, and not water, pass through the filter.

I also found a steam distiller on freecycle.

I'm going to try a bunch of different ways, just for fun.