There many commercial tools to create amazing Icons for your Apps. E.g. IcoFX used to be a good Icon editor, however it is not free anymore. Well, you do not need to buy such expensive tools because open source icon editors and tools such as GIMP, Paint.Net, InkScape etc. can create amazing Icons and in few minutes. Here are some tutorials for you to get started.
Gimp tutorial on how to create amazing looking icons
Paint.Net with Icon plugin for editing Icons.
Inkscape is another powerful graphics editor with great icon creation capabilities
There other creative image editors and all of them can create or edit ICO/Icon files easily. Check them out here.