Actions to be done after the debootstrap --second-stage. It is to finish the installation. This page should be generic, so it will useable for all devices. (Device specific notes are on the device page)
Configure the locales for your preferred language
Switch config tool
Your debwrt device may have a network switch. You could be fine with the default configuration.
For configuration the network switch for your (special) purpose you will need a switch config tool. Examples of such programs are robocfg and swconfig. You have to install it yourself.
How to cope with firmware is really really hardware specific. See the device page or create it ...
Activate Dependency based boot sequence