I think I read somewhere that the best place to add a layout handle for a custom module was through the local.xml file in layouts folder. However, almost all modules that I have seen, never has one used the local.xml. Is it the best practice to use local.xml?
Do you have a link to an article explaining this practice? Also, say I just want to add a lone js/css file to the layout on every page, would local.xml's default handle be the best practice to do it OR what is the best approach for it?