i never played for just skill gain, aside from doing the new haven quest.
it didnt take long tho, few hours in doom. i also got 3 arties. it was pretty busy down there. now days you could do the moonglow thing, just shoot and run.
while i was in new haven i gmed magic resist. this was a big help.
i also did the bushido, chiv, tactics, anatomy, healing quests to get those skills up. took me only one day to get all those skills in the 60s.
load up on hci items a really fast repeating xbow (you can even get hci right on the bow) and get your dex up to 125.
at this stage doing alot of dmg isnt as important as hitting what your shooting at.
putting a few quiver of elements in your pack lets you hold alot of arrows/bolts. plus they can be insured.
once you get to 75 you can do the golem thing, but i think it takes alot longer and you use alot more ammo. plus you get no loot, or arties.