In a previous post I detailed the process for using a cut down version of the task sequence to test application installation, unfortunately this process has not worked for a number of people so I thought I should add the following tip.
If you leave any folders behind then make sure that you remove any conditions. A example of this is the folder for the state restore phase, when using the custom task sequence BDD will see that it is not in the state restore phase and skip the folder. This means that non of the tasks in that folder will be run. The screen shot below shows the condition that should be removed.
Another good tip is to leave the "Gather local only" task in your task sequence as this will then ensure that the BDD environment variables are collected. These are then able to be used by other scripts.
UPDATE - 01/09/08
MDT 2008 now includes built in support for custom task sequences and you do not need to use this process.