The foamies give a good general fit on the ER6. With the double flange, it is very difficult to get a good seal. The triple flange design on the ER6i is much easier to get a good seal with, but unless Ety makes those available for the ER6 model, that will be of little use for you. You could maybe ask them to do this though...
Second point: the ear canal of each user is a bit different. For me, I found that pulling my earlobe up and out drastically actually made it more difficult to get a seal. A very slight pull made it easier for me to find the location and follow the shape of my ear canal in insertion.
Third point: the ER6 has different sizes of foamies. Try all three sizes and see which one works best. You can't get them all the way into the canal so you are trying for the best seal of the outer canal. This is expensive ($15 for each of three sizes) but once you find the right size, you will be set. (And also each canal may need different sizes if your ears come from the Divine Mixed Pairs Department...)
Fourth point: do the hum test. With a good seal, when you hum, you should hear the noise echo in your head as if you were underwater. If you don't get a deep hollow sound to your humming that seems to echo, you do not have a good enough seal. The finger rub next to ear test is not very helpful for me, but the underwater hum works like a charm.
Final point: bass in the ER6 is very underwhelming. Low extension is barely noticeable, and even mid bass has far less impact then virtually any full size phone. What the ER6 offers is detail, soundstage, and clarity. Bass impact is really not their strength. However, the shrill highs should definitely go away once you find the right foamie.
good luck,
des
