I usually end up mling in alot of groups simply because mage = packhorse b/c of those bags lol. Generally it doesnt seem like it would be too beneficial but you can grab the scythes and claymores (mastercrafted of course) that drop, as well as other heavy salable trash as well as hold a massive ton of plat without really having any ill effects for quite some time, and even then its like "so what...i sit..i stand nuke something alot...then wash rinse repeat" whereas anyone who is in a position where they're weight limited b/c they're getting hit really doesnt particularly want to be encumbered. So generally I run it where if I get filled up with the heavytrash (around 40ish mobs or so), I continue to loot the mobs plat and stackables, then get another caster (if there is one) to start looting weapons, then clerics etc etc. More often than not the problem I've seen is not that someone forgets to distro loot, but rather 1-3 people just split right afterwards and log...more than once I've been typing "so here's what we got .......blah blah stuff" and see
xxxx says to the group l8r
xxxx leaves the group
*porty neck fx*
and you just kind of go..ummm...ok? Generally though I think the best etiquette comes down to split platz after, be kind to the monks (ie no autosplit, keep a general amount of plat on hand so they can change to higher coinage if you end up splitting and staying, for example if one or 2 people leave and get replacements), Gems depends on the group, usually I end up rolling them with 6 gems for example everyone roll 1st gets most valuable (or pick if they need reagents or are a jeweler or something) and so on, valuable stack trash just gets split unless say you pick up a mess of spells and its an off number and you need something else to throw in. Items as far as groups go highend not alot of people I generally group with need so most of it ends up as salable trash. If someone does need it obviously it would go to them. If 2 people need it generally I go by a roll situation, unless its an all guild group whereas I would go by the "so whatcha already got?" sort of method (and when I say need, I obviously mean its an upgrade. Common sense rules of course do apply, like my mage doesnt have healing increment...while it would be handy, and a nice thing to have, if theres a healer with a lesser hi item or a pally or beast with the same situation they get dibs). Most people however that I've grouped with tend to go by those very simple and courteous rules in the first place, so theres really no need to designate things. More often than not I've seen
xxxx tells the group: Staff of terrible crappedness
ooo tells the group: oh man...that blows lol you take it
Now as for nodrop things for faction and whatnot I've generally seen alpha used simply b/c its easy to keep track of lol. Though I am relatively loath to suggest it, as it seems not so much a coincidence then that I usually end up looting first in that situation lol, except in the case of grouping with aalasia lol.