Making a new marking menu is a two step process: first you create the marking menu. Then to actually use the marking menu you assign it to a hotkey or to a region of the hotbox.
You can add multiple versions of the same tool with different settings to a marking menu. For example, you can add a Sculpt Surfaces Tool with the Push option selected and another Sculpt Surfaces Tool with the Pull operation selected. This only works with tools, not regular menu items (actions).