Use flags are in the USE variable located at /etc/portage/make.conf.
After changing the USE flags, use this command to recompile all the packages to reflect the new flags:
emerge --update --newuse --deep --quiet @world
/usr/src/linux-<version>-gentoomake menuconfig to configure your kernelmake -j$TC && make -j$TC moddules_install && make install (where $TC is the thread count, i.e. the number of cores in your CPU+1)grub-mkconfig -o /boot/grub/grub.cfggenkernel initramfs to update your initramfs
emerge app-shells/zsh
You'll also want to install the app-shells/zsh-completions package too. Add the following to ~/.zshrc to enable those additional completions:
autoload -U compinit promptinit compinit promptinit; prompt gentoo
sddb stands for Simple Desktop Display Manager and provides us with a login screen and runs as a daemon.
Use the command /etc/init.d/xdm restart to restart xdm/sddm. (TBH I'm not entirely sure what the relationship is between these two components.)
eix is a useful command for searching portage packages. Install it with ''sudo emerge app-portage/eix``.