I just whirl it around, to get as much water out as I can, and then hang it up and let it drip. Sometimes there's still little drops of water in there, but I don't worry too much about it.
Not as often as I probably should, maybe once a year. In fact, I'm probably overdue. I usually pump PBW or Oxiclean through it after I'm done with it. If I can let it soak I do, but, since I usually clean at the end of the brew day, and don't let things sit, I don't normally soak.
I also whirl it around and hang it on a close line to dry. The key is to immediately run water and sanitizer through it right after siphoning. This prevents stickiness from staying on the inside and the tubing will last longer.
Pre-boil hoses get hand rinsed thoroughly with hot water and hung to dry. Wort chilling hoses get oxiclean pumped through them for 30 minutes (sometimes twice especially if using hop extract) and then 2 rinse cycles then hung to dry. Cellar hoses get soaked in oxiclean overnight every use and rinsed with hot water then hung to dry.