Manage the Look and Feel of SharePoint Online Sites and Galleries
Sometimes the default look and feel of the site may not suit your needs for one reason of another. You can easily customize your site with out-of-the box features that do not require coding. You can edit the title, description, and icon for your site, give it a new theme, reorder the left navigation, and customize the top link bar (or the horizontal navigation). Go to Site Actions→Site Settings.
The commands are available under Look and Feel.
As a site collection administrator, you have the ability to manage the galleries in your site collection. These galleries include site columns, site content types, web parts, list templates, master pages, themes, and solutions. You access the galleries by going to Site Actions→Site Settings.
As with content types, you can create a new site column to represent an attribute or metadata for a list item or content type. When created, the site column can be reused in multiple lists, in multiple sites within the site collection.
One of the handy links in the Galleries group is List templates. When you see a SharePoint list that you like and may want to reuse, save the list as a template and then add that template in the gallery. After the template is added, an icon for the list will be displayed as one of the options when you create a new list.
To save an existing list as a template and add to the gallery, follow these steps.
Go to an existing list.
Click the List tab under the List Tools menu on the Ribbon.
Click List Settings.
Under the Permissions and Management group, click the Save list as template link.
In the Save as Template page, enter the file name, template name, and description.
If you want to include the content of the existing list in the template, check the Include Content box. Note that the more data you have in your template, the bigger the file size will be and may cause issues loading the template. We recommend leaving this option unchecked.
When the saving process is complete, a notification will be displayed confirming successful completion of the operation.
You are taken back to the List Settings page.
When you go to Site Settings→More Options, you will see the new template you added under the List templates.
If for some reason you do not like the master page template that’s applied to your SharePoint site, you may need to hire a designer to create a new master page. You then load the new master page into the Master Page Gallery as if it were a document in a document library.
Web parts, themes, and solutions require technical know-how to create but after you have them, you can easily add them to the Gallery as if they were list or document items.