A Handy-Dandy Checklist Stolen From Esquire.com:
1. Shoulder pads end with your shoulders.
2. Your flat hand should slip easily into your suit under the lapels when the top (or middle) button is fastened. If you put a fist in, the suit should pull at the button.
3. The top button of a two-button suit — or the middle button of a three-button suit — should not fall below your navel. [YES LORD!!! – PB]
4. With your arms at your sides, your knuckles should be even with the bottom of your jacket.
5. Jacket sleeves should fall where the base of your thumb meets your wrist.
6. Between a quarter and a half inch of shirt cuff should be visible.
7. One inch of break on your pants hem. Unless you’re going for skinny short pants, which you should do with MUCH care.

If you’re buying a suit with a skirt, be sure you know where the skirt will hit when you’re sitting down. When you get the skirt hemmed, sit down in a chair opposite a mirror after the skirt is pinned up. Many professional meetings take place with chairs arranged in a circle, which might mean being seen from an angle you hadn’t counted on. [Yes!! Sage advice! – PB]
Random suit question: I know that you prefer to wear separates to suits. What sort of occasions do you think a suit is best? Memorial services? Graduation invocation/benedictions? I also like wearing them when I’m surrounded by male colleagues wearing suits and ties. [Yes, I think that’s a great time to wear them. I think they’re a safe go-to for most professional occasions. I am disappointed when I see women wearing them when snappy separates would be so much more interesting and provide an opportunity to say something about who they are, but I get it: suits are an easy uniform and they’re entirely appropriate, even if one is somewhat over-dressed, so much better than the too casual mistake. – PB]
Thank you for this timely advice! I received the suit of my dreams from a dear friend, and now I have a list of where the new hems need to go. [Isn’t that nice? Enjoy! And send us a photo, how ’bout? – PB]