1. The Eclipse plugin makes life much easier so use it. If you are used to Intellij IDEA then try out the Intellij IDEA keymap for Eclipse
2. Some information about signing keys:
   • You don't have to get signing keys to make a deployable application
   • They are inexpensive
   • If you do get the signing keys you will have access to libraries that you otherwise can't use
   • You will need the JDE installed even if you have the Eclipse plugin installed as explained here
3. When sending apps to the background:
   • Make sure you don't exit() the app, only call Application.requestBackground()
   • Make sure to provide an exit menu option
4. Install the MDS emulator. You need the MDS emulator if you plan to do anything that requires a network connection.
5. If you need SOAP support use kSOAP. There is a good DDJ article with examples on how to use kSOAP in a mobile setting.
6. Use Display.getWidth() to make your custom items look correct on any device. Keep the following in mind:
   • Make any static graphics you use that need to span an entire screen as large as the largest device size
   • I have created a list of BlackBerry device screen sizes
7. The BlackBerry has an embeddable browser. There is a good example post on how to use it.
8. Spend time to make a splash screen. The knowledge base has a good article on making a splash screen.
9. Make good looking icons and make sure to also define the rollover icon.
10. If you need charts in your application take advantage of the device always being connected to the internet and give Google Charts a try.

This is what the complete iPhone UI template set looks like:

As you can see it has all of the standard UI elements of the iPhone.

Using the stencils is easy. Open the SVG file with Inkscape and then create a new empty project. Select the UI element you want and copy it into your project:

Knowing some of the Inkscape shortcut keys helps a lot in creating your wireframe. Being able to align and move elements in z-ordering is much easier if you know the correct shortcut keys to use.

Here are a few example images that I made using Inkscape for a demo application:

If you are new to wireframing it is worth reading the 20 steps to better wireframing post by Think Vitamin. One of the 20 steps is not to worry about making your wireframes look exactly like the final product. If you need it to look perfect then using Interface Builder is probably going to work out better.

As a side note I wish Inkscape had a resource for stencils like OmniGraffle does. There are any number of people who publish stencils on their blogs and there is even a site specifically for OmniGraffle stencils. I would add stencils to my list of tips for creating diagrams using Inkscape if it existed. Right now it is seems like the best option is to look for SVG formatted stencils. The gstencil format doesn't seem too complicated so maybe someone will eventually find a way to convert the contents into SVG where they could then be used in Inkscape.

Update: If you have Adobe Fireworks or have money to spend on doing this you should check out this video on building mockups for the iphone using Adobe Fireworks.