There are a few ways to create long shadows in Photoshop, but one of the most popular methods is to use the Pen Tool. With the Pen Tool selected, click and drag to create a line that extends beyond the edge of the object you want to cast a shadow from.
Once you have your line drawn, go to the Layer Styles menu and select Inner Shadow. In the Inner Shadow options, set the Angle to 120 degrees, the Distance to 12px, and check the Use Global Light box. Finally, set the Opacity to 100% and click OK.
You can also create long shadows using the Drop Shadow layer style. To do this, simply go to the Layer Styles menu and select Drop Shadow.
In the Drop Shadow options, set the Angle to 120 degrees, the Distance to 12px, and check the Use Global Light box.
Both of these methods will create a long shadow that extends beyond the edge of your object. You can experiment with different settings to get the look you want.
Conclusion, there are two main ways to make a long shadow in Photoshop: by using either the Pen Tool or by applying a Drop Shadow layer style. Experiment with different settings until you get the look you want!