in case you did not yet have the opportunity to or simply not yet decided to listen to the TechEd Session UXP201 from Las Vegas Oct 2014, you now have the opportunity to fix that watching the attached video. I briefly start to put SAPUI5 into the context of SAP UI Technologies, then you get an overview of SAPUI5 and afterwards the focus is set to implementation best practices. As many planned innovations seen from the perspective Oct. 2014 have already materialized, the section of code best practices has to be updated and extended. Please see the latest preview of the UI5 release 1.30 (being 1.29.1-Snapshot) on http://openui5.org/download.html respectively the news in http://openui5.tumblr.com/post/121579731137/first-preview-of-openui5-1-30.
So after having watched the video for the overview, please spend some time on the blog above and carefully study the extensive new UI5 tutorials and best practices. This will give you many assets/hints that you most likely missed so far.