If picking an item up before you are supposed to during your adventures breaks quite a few quests, than make those objects non-interactive until the proper quest phase is active.
From just reading the forums, most of the bugs are related to an item as such.

The other major bug that I have seen during my own experience in Skyrim, would be changing out NPC's in the cities depending on who has taken over (aka stormcloaks or imperials).
There are many quest turn ins that are broken right now for many people, because they helped either the imperials or the revoulution take over a city. Just doing this removes certain npc's needed for completing a quest.
The simple solution for this, would be to change the allegiance of the npc's that are NEEDED for turning in quests.
If not that, than simply replace the npc with one whom you can turn the quest into based on who has taken over the city.

Thanks for reading,
I hope Bethesda takes a look.

^^^

I'm actually surprised no one else has commented on this.

Yeah... bumping

This man talks sense!

Indeed, make it so that the quest items cannot be collected untill that quest is started, and make sure bosses don't appear untill that point either. Sort of like phasing. I beleive there were a few instances of phasing in the game.

Also, shopkeepers and questgivers that die often "give over" the property/quest when killed, so why not apply this to the NPCs that are kicked out of the cities they are in too?

bump

Yeah, svcks you gotta really play carefully to not bug the game up. Save often also, if you run into bugs...run!

I've been playing slow and carefully from day one and haven't had too many problems. Just weird (glitch in the matrix) instances.

Actually I like that I can run across some random cave or whatnot and find a nice item or whatever that's part of a quest. I think the real issue is that they didn't properly deal with what happens to each quest when things are done out of order (in as much as they can be without needing to do another step first). I found this one ring in a cave on a bear (or maybe it was on a body/in a chest) and suddenly I got a quest update to return to some tavern or whatnot... just out of the blue, and I had no idea the quest even existed. It's things like that that end up allowing things to get bugged and break quests.

What they should have done for each and every quest that could possibly be started out of order is create an alternative quest message (like they did for a select few quests I have run across). Just something like "You have found a rather unique looking ring, perhaps someone is missing it?" or whatever... just something to let you know you found a quest item and not just some loot. Just something to let the game be able to handle such situations without bugging things out.

I'm no programmer, but I know that if things are capable of being done out of order and you don't allow for the possibility, and make the proper changes, then you are just begging for a world of errors.