Add additional web-part to NewForm / EditForm

If you want to add any additional web-part to NewForm / EditForm of a List, type &ToolPaneView=2 at the end of the url. Instead of opening a page in SPD, this could prove a handy approach.

example:

http://server/Lists/SampleList/NewForm.aspx?RootFolder=%2FLists%2FSampleList&Source=http%3A%2F%2Fserver%2FLists%2FSapleList%2FAllItems%2Easpx&ToolPaneView=2