It always seems to take ages, especially when I am trying to get out the door for a nice early morning ride! (even if I lay it all out night before)
I have:
Sports bra (even more difficult when you wake up hot and clammy!)
Chest/HRM strap
Bibs
Jersey
Socks
Bike shoes (clipless so can't just go in trainers)
Head/sweatband
Helmet
Glasses
Fill water bottle
Turn on Garmin/lights
Keys
Probably something else I have forgotten