Having a new DSL element type you can simply add the appropriate button to the palette of any desired diagram type. For this, you must make certain changes in the customization profile.
To add the button for creating a DSL element on the palette of relevant diagram type
Set the DSL element type as the customization target.
Drag the DSL element type to the shape of the newly created customization element.
Create the Place on Diagram Palette attribute for the customization.
If you want to add several new buttons and organize them into a group on the palette, create a new Group package by clicking the Create Group button (see the screenshot on the left). As a result, the button of the DSL element type appears under the Group package (see the screenshot on the right).
If you want to undo the creation of the group, simply click the Up or Down button.
As a result, you can see the new button on the diagram palette. If you work in a collaborative environment, other users, who work with the same project or the projects that use the same customization profile can see the new button instantly after updating their projects.
If you repeat the procedure to add more buttons within the same group on the diagram palette, you can see the appropriate changes as shown in the following figure.