Anyone who wants to create software that looks and feels “professional” should study the various human interface guidelines (HIG) available on-line.
For example, the following are some guidelines published by some well-known organizations:
- Apple Human Interface Guidelines
- Java Look and Feel Design Guidelines
- NASA User-Interface Guidelines
- Windows Vista User Experience Guidelines
One of the coolest things about the Internet and on-line collaboration tools is that content can be created by communities of users that share common goals and interests. An example of this is the new IndieHIG project and their IndieHIG Wiki, which aim to develop community-based guidelines and tools for Mac OS X software user interface developers.
Since I’m actively working with other JKI developers on making VI Package Manager one of the absolute best looking LabVIEW applications, you can be sure that I’ll be keeping my eye on the IndieHIG Wiki 
Nice article once again Jim. I agree that user interface design is maybe the most important part of software design process of interactively used applications. Also VI Package Manager is from the user interface point-of-view the best LabVIEW written application I’ve seen, you have done your job well. I got inspired by your article and wrote an article Designing LabVIEW User Interfaces with Hand-Drawn Paper Mock-Ups to my blog at Expressionflow
Thanks, Tomi. Actually, you’ve inspired me to write a follow-up to your article, as well. I won’t let the cat out of the bag, yet, but it’s coming in the next day or so