How to add / combine multiple custom shapes into a single smart object in Photoshop tutorial (for CC 2017 2015 CS6 etc)
This tutorial is for CC 2017 / 2015 etc as smart objects were only added with the fairly recent versions of the application. You can turn a single custom shape or multiple custom shapes into a smart object. You can use all kinds of custom shapes such as zoom / manga custom shapes and super twirl custom shapes and curved torus custom shapes for Photoshop and elements (of course, you can also use other presets as well)
Firstly, a smart object can be made up of all kinds of different elements such as type and paths and images etc and the great thing about the smart objects is that they can be edited at a later point and the smart objects can also have effects and adjustments added and removed in a second via the layer panel
So if you have multiple Photoshop custom shapes in your image and you want to turn them into a single smart object (this is not the same as selecting multiple custom shapes and then using the combine to turn them into a single Photoshop shape, the shapes are still separate and unique elements within the smart object. So if you have two custom shape layers (and they can be seen as separate layers in the layer panel) then simply go over to the layers panel and then select both layers and then go to the layer menu and select the smart objects command and convert to smart object. You can also add type to the combination of custom shapes with the smart object, so just select the custom shapes layers in Photoshop and type layers and then go to the convert to smart object command.
You can also add a smart object to a custom shape in Photoshop and turn that into a smart object via the convert to smart object command
Items shown are from Christmas custom shapes
If you want to edit this grouping of custom shapes in Photoshop, you can just go to the layer panel and double click the icon and the two or more elements that made up the object will be again accessible and will be (if a vector layer) editable. You can also then add additional elements to the same item. If you do edit them and wish to make the changes to the custom shapes permanent, close the opened PSB file and the smart object will be updated
Smart objects in Photoshop can be collections of all kinds of resources and the key thing about the smart objects is that they preserve the data. The smart objects are not miracle machines, they have to be used at the correct size etc and sometimes the results are not always useful but for custom shapes they are a really very good tool for grouping and manipulation with filters and adjustments.
Smart objects were only added recently in Photoshop (so don't expect to see them in version 6 but definitely CS6).
You can make smart objects of smart objects and of smart objects and so on and you can then edit them via the layers panel (personally I wish there was a nicer way of doing this with perhaps a smart object panel showing all the individual wrappings of smart objects down to the individual elements)
Smart objects are not in Photoshop elements
You can find many other tutorials such as how to combine multiple gradients using blending modes and how to use the Photoshop brushes across channels tutorial and how to define / create Photoshop patterns in CC 2017 2015 etc