With EasyLayouts you can create language specific output layouts as well as language specific article editing pages.
The easiest way to create a language specific layout is to create a base language layout and then duplicate it and change the language it relates to.
Your customisation can be as simple as changing labels for fields and headings etc. or a completely different layout that is more appropriate to the language e.g. an RTL layout may be quite different to a LTR layout.
If you want to translate custom fields we have a helpful Translating Custom Fields in Joomla you may want to read.