Alright, hit me with all of your walk-up permit info/stories/warnings/encouragement/advice :)

I didn't get a permit for July, but I'm pretty determined to do the JMT. I know there are 10 spots a day for walk-up permits. Has anyone successfully obtained a permit this way during high season (late July)? How did you plan your resupply boxes/shipping? Anything specific to consider? Thanks! You guys are great.