SQLCAT (new look and feel:-)) gives us a new best practice to Microsoft® SQL Server® Integration Services (SSIS):

1. SSIS is an in-memory pipeline, so ensure that all transformations occur in memory.
2. Plan for capacity by understanding resource utilization.
3. Baseline source system extract speed.
4. Optimize the SQL data source, lookup transformations, and destination.
5. Tune your network.
6. Use data types – yes, back to data types! –wisely.
7. Change the design.
8. Partition the problem.
9. Minimize logged operations.
10. Schedule and distribute it correctly.

within a lot of linked articles.

http://sqlcat.com/top10lists/archive/2008/10/01/top-10-sql-server-integration-services-best-practices.aspx

CU tosc