Those are great pieces of advice already!! I'm with what cvp3 said about making them as insect-proof as possible. The last one we built, wasn't heavy or over-built, but we did it RIGHT with no gaps around the door/windows/roof, etc. I absolutely HATE going to a shooting house in the dark, even when it's cold, and there being wasps huddled together on the wall. More than anything else, insect-proofing it was my priority last time. Maybe I'm just girly!

This is expensive to buy, but my father in law owned a flooring business and lots of old boxes of carpet tile. 2' x 2' squares of commercial carpet with rubber backing....we used flooring adhesive and put it on the floor and interior walls up to the window. It sound dampened movement very good, and I suppose also gave it a little bit of insulation (although I guess that don't matter really).

I do NOT leave my chairs in there year round. Again, makes my skin crawl thinking about spiders being in them.

Some friends of mine had buzzards roost in one of theirs over the summer, basically ruined the house to the point of being unusable. They sprayed it with Clorox and everything, still can't kill the ammonia smell.