Twelve (12) emerging best practice for adding user experience work to agile software development

1. Drive: UX practitioners are part of the customer or product owner team
2. Research, model, and design up front – but only just enough
3. Chunk your design work
4. Use parallel track development to work ahead, and follow behind
5. Buy design time with complex engineering stories
6. Cultivate a user validation group for use for continuous user validation
7. Schedule continuous user research in a separate track from development
8. Leverage user time for multiple activities
9. Use RITE to iterate UI before development
10. Prototype in low fidelity
11. Treat prototype as specification
12. Become a design facilitator

I also liked some Agile quotes they had on successful software development:
1. Start sooner
2. Build less software