1 yes practice 2 light weapons level 3 = 65 percent spread & 1/2 pistol recoil 3 don't adjust for screen shake! 4 i see less hits register with high ping (packet loss?) 5 it seems more hits register with high fps. 6 cl_maxpackets never really helped me much.
Hmmm Dont know if it's allowed in ET but RTCW has a few tweaks that improve headshots. r_lodCurveError . usually set to 250 Yes I know all the technical answers on what this does regarding polygons but what a lot of players dont know is it actually helps reduce bullet spread.... Trust me. If it's allowed on the server you play, adjust it to max allowed value usually "9999" and you will see that actually does improve headshot capability at a distance. Only trouble is you have to be good at aiming for the head in the first place... which takes a lot of practice and then some! Noobs tend to miss more because of slack assed aim. In the hands of an experienced player it is deadly
I tend to find, at least on Jaymod, that aiming for the top of the head is the best. During the course of a firefight my crosshair tends to slip down, but if I conciously keep it up, I get more headshots.
Tilt it up slightly higher, before the firefight, whilst roaming.
I pretty much only kill by headshot now. It's pretty simple actually, when you come under attact, don't panic, strafe and get your crosshare perfectly aligned with their head, then just spray while straffing but obviously moving your mouse to follow the spray. It may sound hard but it really is not.