My packing lists tend to follow seasonal conditions, and blur in the Spring and Fall when the weather is a pot pouri. Perishable things like fuel and food are adjusted every trip, but the rest is pretty standardized based on the season. (Water procurement is different here in the winter than in the summer, for example, as is clothing requirements.)

I think first in terms of packing/gear/supply categories (like water, shelter, fire, food, rescue, light, tools, first aid, hygiene, etc.) Once I define the need I let that drive the specific items I pack.

That's when my overpackingitis flares up. I'm very good, IMO, at making sure that I've covered all my primary requirements, but tend to overpack with multiple redundancies because, as my hubby observed last night, I love my gear. I hate choosing between it. Two favourite snuggly bush sweaters? Pack 'em both!

BTW, if it seems like I missed the "non wilderness" part, I didn't. I tend to think along the same lines regardless of when and where I'm traveling, although I bring more the further off-road I go.