How can I set a default view option for all finder windows in Lion?

Open up a Finder window, CMD+J, set it up as desired, and click on Use as Defaults. Do note that will only apply to windows that you've not opened before. If you want to apply that to all previously opened windows, you need to remove all the .DS_Store files which store that data for each previously opened folder. To do that, launch the Terminal app (in /Applications/Utilities/), copy & paste this command into the window that pops up, and hit the return key:

sudo find / -name ".DS_Store" -exec rm {} \;

At the Password: prompt, carefully enter your admin password, since nothing shows up on the screen, and hit the return key. When the default prompt, usually the $ sign, pops up, quit the Terminal app, restart, and open a Finder window, set it up the way you want, and click on Use as Defaults. All subsequently opened or created folders should retain that view.

In Icon view there is a size slider in the lower right hand corner of the Finder window.

http://macs.about.com/od/usingyourmac/ss/Setting-Finder-Views-For-Folders-And-Su b-Folders_2.htm

http://support.apple.com/kb/HT4103

It's not working, there still many folders act like the same... not following the "use as default" check.