I warned you in the title – these are VERY BASIC mods (I don't even know if you can consider them "mods") but here they are: (more to come for sure as I get more handy)
Paper towel holder (screwed into the bottom of the top cupboard)
Collapsible shelves (from Wal-Mart) in the closet – perfect width and height – one shelf for each of us
TP holder (3M hook/loop) and new shower curtain
Over the door hooks
Fly swatter on a 3M hook
Baskets in the pantry
DD's bed (we doubled up the mattresses from both bunks since we won't be using the top bunk to sleep on – just more storage)
And finally, not a mod, but the whole package (for now since we are looking to trade up our TV)