You may run into the following error message when creating your own Live ISO image.
Error creating Live CD : resize2fs returned an error (1)!
This occurred about half way through the image creation process and caused it to terminate without creating the ISO image.
The problem is that the amount of hard drive space available in which to perform some of the final resizing tasks to minimize the final image size is too small. Despite having used partitions that had over 10 or 15 GB of free space for both temporary and cache space for the livecd-creator command, that was not enough. I finally specified a partition that had over 100GB of free space out of frustration. As soon as I did that, the problem was resolved and the image was created.
I used the following command to create the image and specify the location for cache and temporary space. Note that it should be on a single line when entered.
livecd-creator --verbose --config=fedora-live-kde-MTC.ks --fslabel=Fedora20-Live-X64-KDE --cache=/Virtual --tmpdir=/Virtual
The specifics of your command will vary, but you get the idea.