Workflow development - sharing our experience

I would like to highlight several items that we've learned after developing several complex workflows for our customers.

• Start with workflow design, email notifications and email templates definition, define PDPs and fields that are required / visible on every stage
• Create fields dynamically if possible, so your workflow can work on different environments (dev, staging, production)
• Send notification emails on every change of control or change of ownership
• Change Project Owner if your workflow expects more than just and approval
• Check-in project when change ownership
• Use SharePoint mail for sending emails (Project Server Notifications could be disabled)
• Use event log for logging every steps in your workflow (helps to debug it); Log emails sent by workflow (who, when, where). More you log  - more stable and tested your workflow is since debugging is not an easy one.
• Use automated deployment scripts for installing workflow
• Backup previous versions of workflow before installing new ones

Our team is using FluentPS (http://www.projectserver2010blog.com) (we are developing and maintaining FluentPS) for workflow development and deployment, access to Project Server 2010 data, field info access / value modifications. Sounds like an advertisement - but FluentPS saves us a lot of time; you still can do everything with pure PSI.