One of the biggest ways I keep from having to recode for different sizes is by never using exact numbers. Instead of putting something in the middle of the screen using say 150 dip I use 50%y. By always arranging my views and such by percentages it usually works out pretty well. There are some minor tweaks needed every so often but for the most part works across many devices because the overall length and width are proportionate. course there will always be exceptions to the rule but it works for me for the most part. By never setting anything in stone it seems more fluid across multiple devices.