I'm a sentinel and as a pure dps class its almost impossible to find a group by simply posting DPS LFG HM FP in general chat
BUT if i group that healer thats doing so in general chat, i can easily, within 10mins, form a group and go to the instance, even if im not in a guild and do not have many people on my friend list... how ? easily, use the /who tool !
once i have a tank or a healer, i just /who class 50, prepare a generic "hi are you tank spec ? if so want to run Y FP ?" and send it to the first 20 on the list who arent in a FP or an ops !
Also means i can form a group with the most diverse composition possible (the 4 classes being present) to minimize wasted loot. Once i have tank and healer, finding a spare dps is so easy heh...
If a dps can do it, you can bet a healer or a tank can !