There are two quests that will get you an easy +16 worth of int, for enchanters.
A dark elf enchanter can quest the stein of moggok at level 8. A non-DE enchanter can do it when they get Illusion: Dark Elf. The stein is +10int. It's an easy quest and there are no monsters above level 3 to fight. You have to kill some bixies, and run back and forth accross antonica a few times, that's about it.
When you are near Queynos for the stein quest, there is a quest there that gets you a +3int earing. All you have to do is jump in the pool of water near the bank, swim into the sewers and camp Cuburt for a few hours, nothing there is above level 5 so it's totally safe. Do this twice and you'll have 2 +3int earings.
Total, that's +16int at almost no expense, I think you might even make a profit on the Stein quest because one bartender gives you 4pp or something... but you burn lots of food running around and sitting in the sewer.