#48 (I think)
When soldering ledengins, you must have lots of patience. personally, it takes me no less than 45 seconds to do 1 joint on an ledengin from room temperature. Most people would say that number is pretty high, but I don't turn my iron up that much. The key is to heat the underside of the pcb star with your iron for a bit (I've heard 10 seconds thrown around, but that's never enough for me) before you start to solder the pads. If your iron sticks to the solder on the ledengin, you didn't heat up the bottom of the pcb star enough.
#49 (might be in there already, pertains to #48 though)
Don't ever, ever, ever try to solder an ledengin while it is on the heatsink. This is true with any led, but especially with the ledengins. you will not get a proper solder joint that way period.
I was having a discussion with someone who asked for some tips and as I was about to point them here, I realized these two weren't on there. Figured better add them since they come up a lot.
Anyone who wants to add to the ledengin one with how long it usually takes them to heat up the pcb star please feel free. I said 45 seconds per joint for me, but I didn't mean 45 seconds on the underside of the pcb star. I meant 45 seconds from touching the iron to the bottom of the board to the end of the pull test.