Well, luckily the pileups have lessened greatly. The advice given here so far is correct, you need to find out where the dx station is listening. Doing so, I have managed to work these guys on four bands(15,17,20,40) with only a G5rv and 300 watts. The key is finding the last station worked and also discerning what direction the 7o guys are moving. Once that is done, Ive found they are moving in .50kc increments...in other words, if the last station worked was on 18.037.20 the next qso would take place on either 18.037.70 or 18.036.70 depending on direction. When in doubt, plus or minus 1 kc will also work if you cannot find the last station worked. It seems both of the above patterns have existed on all bands except 30 meters, where it seemed they were taking calls at random(probably only stations they could actually hear). But you gotta find the last station worked to have any chance.
Hope this helps some!