What software is best for GUI design?
Which is the best way to create Icons, Buttons for Mobile Application development ?.
Graphic Design Stack Exchange is a question and answer site for Graphic Design professionals, students, and enthusiasts. It only takes a minute to sign up.Sign up to join this community
The best way? Use Photoshop (preferred) or Fireworks.
There's quite a few questions on graphicdesign.stackexchange.com on the topic. A search might help you out.
For the actual creation of the icons, there are huge amounts of tutorials and content just a simple Google away. Googling for 'icon creation tutorial photoshop' yields literally millions of results.
For the actual creation of the *.ico file, I am a fan of GIF movie gear. A bit dated, but it allows you to fine-tune your *.ico to include different resolutions, transparency and colour depths. Importing *.pngs from Photoshop or elsewhere is a snap, too.