To make a launcher, simply right-click an empty area of your desktop, and choose Create Launcher. You will see firstly there is the Type; just leave it as Application. For Name, put something descriptive that will be the caption you see beneath it on your desktop (and if you plan to add it to your panel as well, it will be displayed as a tooltip when you hover your mouse over it). For an example, we’ll use the eject command, so for Name put something like Eject Disc. For Command, simply put eject, and for Comment, something like Eject the DVD Tray.
Note that the command can have options after it without the need to enclose it all in quotes or anything. Also, depending on the command, you may need to change the Type to Application in Terminal if you find nothing happens when you click the launcher.
Before you click OK, you’ll see a generic icon which you can click on to select one of your own choice to replace it. It should display some basic system icons to choose from, but you can always Browse to a folder where you keep your favourites. Note that if you drag it to your panel, the copy that appears there may have reverted back to the default icon, so you’ll need to reset it.
For a guide to making launchers directly on the panel, click here.