There are an endless number of custom template files you can create, but what makes a template an essential template? 

An essential template eliminates the most repetitive tasks.
The first step you should perform when working on the first sketch of a part is to anchor the geometry to the sketch plane. Typically this is done by using the Fix constraint to fix a node on the geometry, but you can also project geometry from the center point of the sketch and then constrain the geometry to the projected node. The most essential templates are templates that eliminate these types of repetitive tasks.

Fixed Point Template
The Fixed Point template is probably the most essential template any Inventor user can create. It solves the problem of anchoring the geometry of your fist sketch, and it’s easy to create.

To create the Fixed Point template:

1. Open a Standard Part file.
2. Expand Origin in the browser.
3. Right click on Center Point and select Visible.
4. Use the Project Geometry command on the 2D Sketch Panel to project a node from the Center Point onto the sketch plane.
5. Right click on the Center Point in the browser and deselect Visibility.
6. Save the file in the Templates folder in the Inventor program folder.
7. Close the file. You’ll be asked if you want to save the file. Click No.

Once you’ve saved the file in the Templates folder you can use the template by clicking the New icon. The Fixed Point template should be displayed in the New File dialog box. When you open a new file with this template you can use the green snap dot to snap to the node on the origin. This will automatically constrain your sketch geometry to the origin of the sketch plane.

An essential template also eliminates errors.
If you’ve created a custom punches, you know that when you forget to add a center point to the first sketch of the punch source file (ipt file), the punch won’t work. This can waist a great deal of time because you have to add the center point to the first sketch of the source file, and then extract a new punch. You can circumvent this problem by creating a Punch template.

Punch Template
The Punch template is very simple, but eliminates the need to add a center point to the sketch.

To create the Punch template:

1. Open a Standard Part file.
2. Expand Origin in the browser.
3. Right click on Center Point and select Visible.
4. Use the Project Geometry command on the 2D Sketch Panel to project a node from the Center Point onto the sketch plane.
5. Right click on the Center Point in the browser and deselect Visibility.
6. Use the green snap dot to constrain a center point on the projected node.
7. Save the file in the Templates folder in the Inventor program folder.
8. Close the file. You’ll be asked if you want to save the file. Click No.

Once you’ve saved the file in the Templates folder it should be displayed in the New File dialog box. When you open a new file with this template you don’t have to add a center point, and you can use the green snap dot to constrain your sketch geometry to the node on the origin.

Why are essential templates important?
The templates described above are simple and easy to construct, but provide a significant benefit. They save time and prevent errors while you perform the tasks you typically perform.