I'm not a fan of going to a new place, taking my winter jacket off, and discovering it's too warm for a coat but too chilly without it!  A simple everyday cardigan is a must-have for me, especially for traveling and unpredictable weather.  It's easy to layer under a coat and quickly removable depending on the environment.  Long sleeves and a typically looser fit makes it hard to find a petite-friendly style, though.  I found my current favorite at...