There are a lot of ways to make a mockup in Photoshop, but one of the most popular ways is to use a smart object. A smart object is an object that can be manipulated and edited like a regular object, but it has some special features that make it perfect for making mockups. For example, you can use a smart object to create a 3D model of your object. This will give you a more realistic representation of your mockup. You can also use a smart object to create an image of your mockup in different colors or sizes. This will give you different options for how your mockup looks when viewed online or on paper. Another great feature of using a smart object is that you can change its properties easily. For example, you can change its opacity or color. This will make your mockup look more realistic and professional.