Often you find yourself with a workflow that requires a task or an issue be converted to a project or task. However you need the data that exist on the object being converted to transfer over. This will be done automatically, however you will need to be sure that the data fields exist on a custom form that is attached to the new object. The best way to do this is to copy the original object custom form and create it for the new type of object. Example: If it is originally an issue custom form, then copy it for a project type. This will allow you to attach that form to the object type at conversion, which will allow the data to transfer over. Below are example steps for doing this from an issue to a project.
1. Notice the existing form exist on Issues.
2. Once the form is selected click on the Copy button above.
3. I would suggest keeping the same name and maybe adding Project in the parentheses.
4. Make sure that you select the correct object to apply the new form to from the drop down.
5. Once done select the copy button at the bottom.
6. You will notice that the form now exist on the list. Now at conversion from an issue to a project the data on the issue custom form will transfer over when you attach the project version of the form at conversion.