All the elements have the possibility to add additional Tk options. Eg. -height 5 to tell a ListBox how many elements to show. All widgets have a default element, eg. a CheckBox configures the checkbutton as default. The other elements (including packing of these) can be configured with the name as prefix. Eg. the packing of the checkbutton is configured with -pack:option value.
To see a list of options to each Tk element, see the man page for the element, or try a reference card
In the following you can see how each element can be configured. The element marked with a star is the default, and therefore needs no prefix.
It may sometimes be necessary to check the source, to see how to pack a given widget. To do this, look in the file called types.tcl, which is located in the Generator sub directory. Search for pack_widget.