To kick off, I interview the mobile concept designer Alexander Gillis, aka zandog

1. What do you feel makes a good theme for a handheld device?

Regardless of the mobile operating system or launcher method, a theme needs to be complete. A full set of icons, wallpaper, dock, widget styles and sometimes even sound, need to be coordinated and functional. Everyone has their own tastes so the taste of the theme doesn't matter as long as it all fits together well.

2. If you were giving advice to a first time icon maker/theme maker, what would it be?

Understand the environment your working in. Each OS or their mods, have their own set of parameters. Pixel resolution, icon/dock/widget grid sizes and interactive functionality, all play big rolls in creating a intuitive and successful theme. The more you plan ahead and know what your system interface can do, the better outcome your going to get.

3. What would you say is the most intuitive handheld interface right now?

The most intuitive interface is the one you can create for yourself. HTC has Sense, Motorola has Motoblur, Samsung has Touch Whiz and iPhone has.. well, iPhone. All of these interfaces have their benefits in creating a fluid environment in what the manufacturer thinks would work best for their devices. I think what people are really looking for is an experience they can call their own and third party apps are beginning to provide that. If you don't mind jail breaking, the Cydia community has carried the Apple iOS devices for years now when it comes to custom theme design. On the other hand, Google allows any modification to it's operating system and that has opened the door for many interface 'launchers' for the Android operating system. High screen page counts, an endless amount of widgets and on the fly theme changes have given people an almost endless array of different options and configurations. Launcher Pro, ADW Launcher EX and even full system ROM modifications like Cyanogen Mod expose users to thousands complete themes and interactive functions. Users want it their way and this provides that experience.

4. Where's the best place for inspiration on creating concepts and themes?

Well right here on Deviant Art of coarse! Groups like Android-Users, APPLE-DESIGNS and Mobile-Design offer great ideas for piecing what your looking for, together. There are many more groups just like them. Outside of DA, there are a ton of iPhone and Android theme sites. Those key words combined with Google is your best friend on that end. XDA Developers (www.xda-developers.com/) is the largest community for application and customization on mobile devices. I recommend checking that out.

5. I can see you use Photoshop, but what other software would you recommend to other concept designers out there?

Like many different design subjects out there, mobile design should be done on the medium that fits your style and needs the most. 3D rendering applications are great for creating wire frame models in 360 degree and angled viewing shots, many of which make it impossible to tell next to the real thing. Illustrator is perfect for developing high resolution, dynamic objects that come close to the effective abilities of Photoshop with its vector-based editing environment and ability to integrate with virtually any other Adobe application. So it really comes down what the presentation demands and how you'd like to see your concept or theme turn out.

6. Finally, what three things would you say make a perfect conceptual design for a handheld device?

1) Flexibility is the most important element in mobile design, whether its theme or device conceptual design. Getting use to working at very high resolutions and scaling that design to whatever size is needed makes your design the most useful for everyone attempting to work with or use it.
2) Understanding how your device or theme is put together and functions. In every aspect of design, it's very important that people know what your concept can and cannot do in the real world. Many people design stunning visual concepts that will never see the user end of it's development simply because the concept if not functional. Sitting pretty may get your design a few looks but in the end, has no lasting impression or appeal. Remember, that in order to make it work, it needs to have some usefulness outside of your initial design.
3) Take your time and stay organized. The best design concepts come from artists who understand the scope of their project and don't waiver from or rush it. A design may take several hours to complete but it's important to assure it's exactly as you envisioned it without making compromises. Keep track of your layers, their group folders and how they relate to the entire concept design. It's easy to get lost when there is a lot going on in your project.