When working with 3D views in Revit, it is essential to be able to change the size of the view to effectively visualize and present your designs. Here are the steps to efficiently change the size of a 3D view in Revit:

1. Open the 3D view you want to resize in Revit.

2. Go to the 'View Control Bar' at the bottom of the view window and locate the 'Scale' dropdown menu.

3. Click on the 'Scale' dropdown menu and select the desired scale for the 3D view. You can choose from preset scales such as 1:50, 1:100, 1:200, or customize the scale according to your specific needs.

4. Once you have selected the desired scale, the 3D view will automatically adjust to the new size based on the selected scale.

5. You can also manually adjust the size of the 3D view by clicking on the 'Zoom' tool and dragging the view to zoom in or out as needed.

By following these steps, you can efficiently change the size of 3D views in Revit to better visualize and present your designs. This can be particularly useful for creating presentation views, coordinating with other disciplines, or simply gaining a better understanding of the spatial relationships within your design. Experiment with different scales and zoom levels to find the most effective way to communicate your design intent through 3D views in Revit.