You need a Kickstart configuration file to make Kickstart work. The file needs to be in the place you have specified in your bootloader configuration file (see Section Bootloader).
Content of the file is as usual. See the Kickstart HOWTO for further help.
If you want to use the script described in the next section, add the following at the very end of your Kickstart configuration file:
# The Last Thing happening in Kickstart:
# get a file via TFTP which indicates we are done.
echo "get Kickstart_end" | /usr/bin/tftp tftpsrv
Make sure Kickstart installs the tftp package on your clients!
If your clients have write access on your server (for instance via NFS) you could mount this filesystem in a last step, remove the symlink for this client (see Section TFTP) and unmount the filesystem again. In this case you don't need the script described in the next section.