6 Best practices for sitecore information architecture.

My suggestions to have a stable information architecture following this rules:

1. Reference items by ID. Way better to move and rename items. While wokinge in the user interface pathes are more readable.
2. Never use same key in data templates. Keep in mind the this might happen when using inheritance.
3. Follow max. 100 items under a single item. Create subdirectories und organize them.
4. Use Lucene search instead of (Fast) Sitecore queries (= SQL calls affect perfomance)! 
5. Avoid branch templates that can change over time. Branch template don't reflect those updates.
6. Rich Text Editor. Help Content authors to focus on content, not presentation and never on markup. Use provides Sitecore RTE Profiles: e.g./sitecore/system/Settings/Html Editor Profiles/Rich Text Default

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There are way more tips, but those here will help in a first row.