As a general rule, if you can place two hand widths from under your bust to your natural waist you are neither long nor short waisted, if it is less you are short waisted and if more long waisted.
I am a rectangle/ slim hourglass and short waisted (around one hand width from under the bust to my waist. I have a high hip shelf and quite long in the rise (length from the low hip to the natural waist).
My apologies if this is confusing Bree, Angie does have a blog post which if I remember has a diagram. It may be worth a search.
With regards to the pencil skirt, do you just need to have the waist taken in? I imagine this is quite a common alteration for an hourglass.
