Document a model
Warning: The update of the help file does not work for versions 2.8, 2.8.1 and 2.8.2. A bug causes all changes performed with the help editor to be lost. Normally, the next update of QGis should have this problem solved . You can inform the Model Help by clicking the Model Help Editor button in the Graphic Modeller window.

This will open the Help Editor window that has three panels. At the top
is an HTML page with placeholders for the description of the algorithm, and
sections for the input and output parameters. At the bottom left you have an
element selection box, and at the bottom right, a text entry box. To edit an
item, select it in the left window and use the box on the right to enter a descriptive
text. Click OK when you are done.
This help information will then be available in the Help tab when
the tool is in run mode.

Save, load, and export templates Models can be saved at any time by clicking the Save button in the processing modeller window.

Do not hesitate to save your work often … As we have mentioned in the configuration of the modeller, the first time you register a model, you will be asked to name the model file. For updates, they will automatically be made to the saved file unless you want to change the name of your template file. In this case, you will use the Save As … button .

Models
that are not saved in the default Models folder can be opened in two ways:
• By activating the Processing Toolbox panel , navigating to Models
|Tools and then double-clicking Add Model from
File
• Using the Graphic Modeller window and clicking the Open Model button
.

In both options, you have to point to the .Model file.
Models can also be exported as image files. This
is useful if the workflow needs to be presented and included in a report.
To export a template, click the Export As Picture button .

The template will be saved as a PNG file.

Scripts collection
QGIS now has an online collection of models and scripts that can be loaded. In the Processing Toolbox pane, navigate to Models |Tools and double-click Get Models from the Online Scripts collection .

The new models will be loaded in the Models section of the pane under the Models example group .

This collection of online models will be continually expanded by QGIS users.