W8 has a desktop mode, a start screen mode, and a lock screen. Desktop mode is the same as it was in every previous iteration of Windows, and it will still be where you spend most of your time. So that's where Rainmeter, auto wallpaper, all that shit you're used to goes.
Start screen mode is and should be treated as a glorified app launcher, with some shitty native apps that you should delete immediately. The desktop alternative to any Windows 8 app is always superior.
The absolutely ESSENTIAL program for customizing Start is called OblyTile. It's shameful its features dont exist in the W8 shell. It will let you pin absolutely anything to the start screen, and let you decide exactly how you want any start screen tile (launcher) to look. You can find icon sets on Deviantart or elsewhere that will match a theme and make your tiles look pretty and consistent.
If you play games on your laptop, get yourself an app off the windows store called Steam Tile so you can pin them to Start as well.
Finally there's the lock screen. To customize it, follow this incredibly counterintuitive set of steps:
Windows Key+C > settings > Change PC Settings (it's invisibly buried at the bottom of the tab that appears) > Personalize
Under there you can change the image that displays when your computer is locked. If you click "start screen" up top you can change the color and design of the Start Screen's background (I prefer to match it to the color of the desktop theme for continuity). One more tab over is just your same old account sign-in image, only now you can pick any image for it.
Now go down to the Users tab and choose the picture password option. You can set any of your backgrounds as a password, such that drawing or tapping a certain combination on the picture will unlock the account. For example, I used pic related and set a sequence of pokeballs to press.
Make sure you're happy with all the above selections, because it is a huge fucking pain in the ass to change them.
