all very subjective of course, but if SomeJComponent extends (say) JPanel,
I'd be inclined to do setLayout, setBackground etc in the constructor.
(I really see no point to init() except in an
applet context).
createComponents, called from the constructor, seems fine, but you would
also (generally) have your listeners there too.
personally I like to put the gui (the view) together in one method - components,
listeners etc, leaving the bare minimum (if anything) exposed.