Is this a good method before charging a Li-ion battery?

I don't think those batteries have a memory, so it doesn't matter when you recharge them. I don't worry about it, and carry an extra fully charged battery for my camera.

No. Never fully discharge any kind of lithium battery. It's possible they will never work again. Actually, most quality devices have a protective circuit which shuts everything down before they completely discharge.

This story goes back to the days of the nickel cadmium batteries which developed a sort of memory. Lithium batteries are a whole different chemistry.

I think you're spot on! When the battery runs too low, it just stops working. Sometimes, you can wait a few minutes, turn it on, and get another shot. I'm not sure how much reserve is left in the battery, but your equipment is programmed to let you know when to recharge it.

err, i mean, i never short-circuit them because it's a dangerous thing to do but use them until there's almost no more left (most devices put on a low battery warning when the voltage drops to certain level but i takes out the battery and use it elsewhere). i have done this serveral times.

You might spend some time on this site. http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

Whatever you need to know is on there somewhere. There is also a forum called candlepower. I think it's just candlepower.com, though I didn't test it for you.