How do I prepare the interface between SIESTA and wannier90?
The flowchart to compute the Maximally Localized Wannier functions from the input provided by SIESTA is detailed in one of the self-explained SIESTA tutorials located in Prof. Javier Junquera’s web page.
http://personales.unican.es/junqueraj/JavierJunquera_files/Metodos/Hands-on-session.html
This tutorial will also teach you how to plot the Wannier functions.