The debian way (etch packages):
# apt-get install linux-source-2.6.18 kernel-package build-essential fakeroot libncurses5-dev
$ cd /usr/local/src
$ tar jxvf /usr/src/linux-source-2.6.18.tar.bz2
$ cp /boot/config-2.6.18-6-686 linux-source-2.6.18/.config
$ cd linux-source-2.6.18
$ make menuconfig
$ fakeroot make-kpkg --initrd clean
$ fakeroot make-kpkg --initrd kernel_image


Examples:
fakeroot make-kpkg --arch amd64 clean
fakeroot make-kpkg --arch amd64 --initrd --append-to-version=-skx.2008082001 kernel_image