Here are some rules that have made my software experience much nicer:

1. Use as little software as possible. One browser, one text editor, one media player, ...

2. Use the best software available! Use Photoshop for photo editing, use Firefox for browsing, use VLC to play your media, ...

3. Use a plain text editor for most of your stuff. Not a word processor, a plain text editor like Notepad.

4. Use a calendar, address book and to-do list you can sync with your mobile phone.

5. Use web applications for corporate work. In cases you have to work together.

6. Do not use web applications for working on high-sensitive data.

7. Do not run software which is still in beta state.

8. Update your software regularly.

9. Delete Software you no longer use.

These are my rules and they make me happy. Hopefully they make you happy too. 

Image by Hmmlargeart