Using SSIS Variables for:

Data Locations - Process and Archive folders

Server Connections (Dev/Prod) - This is kinda cool, create connection strings using the variables, then when migrating just change the variable(s) (usually the Servername property in the expression for the connection)

After all the SSIS packages are tested and pass QA. We fill out deployment documents and have code reviews. The developer who wrote the package usually never deploys the code.

Last but not least is Stabilization...After the code has been deployed, the developer verifies all the processes are running correctly for the first few runs.

We also schedule jobs using proxy accounts.

If you are working on high visibility projects it is a good idea to come up with standard processes and to follow those processes. Most mistakes occur when code changes are done on the fly and under stressful circumstances.

Good Luck...