For example, I seem to remember there being something about selecting each unit WITHIN a selected group. Like when you first start a game, whats the quickest way to get each worker to go to a different mineral field? I've seen this in some pro replays but have no ideas what keys they pressed.
Also, is there a way to cycle through the different types of units in a group? (without hotkeying each unit as its own group) i.e. lets say I have a group of wraiths, bc's and science vessels, and want to cloack the wraiths, cast irradiate with the science vessels, and start firing yamato cannons from the bc's.. is there a faster way than double clicking on a unit of each type?