I have read many things about supporting multiple devices. Right now I have implemented it in my application, I have made following folders as shown below :
The way you are using is deprecated from android 3.1
. Read the MulitScreen Support
Your layout folder must be as this
res/layout/main_activity.xml # For handsets (smaller than 600dp available width)
res/layout-sw600dp/main_activity.xml # For 7” tablets (600dp wide and bigger)
res/layout-sw720dp/main_activity.xml # For 10” tablets (720dp wide and bigger)
Read the document thoroughly.