I have got bored with TouchWiz, i kind of hate the style and look of it on my Galaxy S2, I was thinking of Rooting and installing Cyanogenmod onto it, but i thought against it. Maybe if Samsung don't update the S2 with JellyBean, ill root, or even buy a Nexus phone. Here's a little guide that can let you have the look and feel of Stock Ice Cream Sandwich/JellyBean.
Launcher - Nova Launcher
I've tried alot of Launchers previously before using Nova, but Nova provides a great look and feel, and is stable enough to use daily, I find it better than Touchwiz. It uses the stock ice cream sandwich look of the home screen and App drawer, which is nice to look at and use on a daily basis. I was going to upgrade to the Prime version of the launcher, which adds more features such as gestures, hiding of apps and different scroll effects. But i find the free version is good to use.
Check out the developers site at : www.NovaLauncher.com
Or on the Play Store: https://play.google.com/store/apps/details?id=com.teslacoilsw.launcher
Icons
With TouchWiz, or any other Skin added onto high end Android devices these days, the icons are different to the stock Android ones you see on Nexus devices. Nova Launcher will allow you to change the look of the application icon on the homescreen. I would love to be able to change the icon of the app in the app drawer too, but i haven't found a way to do that yet. There are alot of icon packs available in and out of the Play Store, but the one i use is the Stock ice cream sandwich pack, which comes with the ice cream sandwich theme, You don't have to use the Theme to use them, but you just need to keep it installed.
By long tapping a icon on the homescreen, Nova will allow you to edit the name and the image of the icon. Once you click the image, it will give you several options on where your customised icons are, The pack i use will be located in the "icon pack" option. From there, there is a wide range of icons that you can use, which are used on Stock Android.
Play Store: https://play.google.com/store/apps/details?id=kov.theme.ics
Lock Screen
I tested Go Launcher and its lock app, Go Locker, to try and get that Stock Android feel and use of the lock screen, but i found it quite hard to find. Then i came across Holo locker, which is the JellyBean android lock screen which is almost identical to the one on Stock Android, it has a quick app launch for the camera, and a general swipe to unlock, with the look and feel of JellyBean.
Holo Locker is from the Developers of Holo Locker, which is also a highly recommended Launcher, i just prefer to use Nova. Holo can also be used on Android versions 2.2 and upwards.
Live Wallpaper
Theres a few Live wallpapers out there to mimic the Jellybean look, but Theres in particular which i have had one my S2, for the longest. the JellyBean Live wallpaper provides the look of the stock version, without any lag or crashes. it also comes with various settings, to change the quantity of animations, the type and Speed of them, the default settings works perfectly.
Keyboard
The Keyboard works well, with the new auto correct implementation, but it crashed a fair amount of times when i used it, so i went back to Swiftkey or the S2 keyboard.
Play Store: https://play.google.com/store/apps/details?id=jellybeankeyboard.f.g
Clock
It provides a nice look and feel, similar to the stock clock. But by reading user reviews, it lags a fair bit, i didn't install.
Play Store: https://play.google.com/store/apps/details?id=com.chilisapps.android.icsClockFree
I feel as though this is the closest im going to get to Stock Android without a Nexus device, i am glad that Developers put time and effort into these themes and looks, its what makes Android better than the rest, right?
*edit* Apex Launcher allows you to change the icon of an app in the App drawer also*
*edit * Nova also has a setting in "look and Feel" where you can change the default icon pack*

