Probably going to be a very unpopular opinion, but I strongly believe that callouts make for a worse and less self-sufficient player. I pugged the entire Eden's Gate savage tier and never once used any form of voice chat in the process. Late in the tier there were a few times where my friend's static had me sub in for them for a kill or two, and the constant callouts that they were doing for mechanics just drove me insane; to the point where I just wouldn't even get in voice with them. Having someone constantly talking in my ear saying what mechanic was happening and what to do for it just bothered me to no end.