This is a list of changes  I usually make after a fresh OpenSuse installation.

Changes in System

Install Oracle Java. Instructions are here.

http://en.opensuse.org/SDB:Installing_Java

Changes in KDE

Add Windows style keyboard shortcut Meta + D to Show Desktop 

Global Keyboard Shortcuts -> Kwin -> Show Desktop

Lock screen with Meta + L 

Global Keyboard Shortcuts -> The KDE Session Manager -> Lock Session

Disable Background Services

Configure Desktop – > Desktop Search -> Uncheck Enable Nepomuk Semantic Desktop

Software Management -> Uninstall Akonadi

Akonadi and Nemopuk consume a lot of resources and result in significant lags in the user interface even in top machines. I never experienced applications opening slowly after disabling these two services. Credit to here.