How do I maintain my oil paint brushes?

Tom is absolutely right, but only if you're a weekend painter. If you paint every or most days it's far too onerous and you'll probably let it slip after a while! Better to wash the brushes in white spirit as best you can and then suspend them in genuine turpentine. You can buy commercial gadgets to do this but an elastic band around the bundle of brushes, a stick of some kind pushed through the bundle below the elastic band, and suspend them in turps in a jam jar works perfectly well and costs nothing. The reason I say use turps is that is your medium, or part of it, so just squeeze out the surplus an away you go.

When I'm done painting, this is how I clean up. I've kept some brushes for years like this:

• Soak the brush in white spirit for a minute or so
• Gently massage the bristles to loosen the paint and make sure as much as possible is dissolved in the spirits
• Put a good dollop of liquid soap onto the bristles, and gently scrub into a lather with a bit of warm water (not hot), separating the bristles to get as much paint out as possible
• Rinse out with warm water
• Repeat if necessary

Make sure the flow of water is always from handle to tip, make sure you're never pushing paint up towards the handle as it can collect there where it's almost impossible to get out, and it will harden and splay the bristles over time.