Business case
You can make your own templates for announcements, knowledge articles and events.
Announcements: It can be useful if you make a lot of the same announcements, with the same image and name. For example a webinar or change in the product that comes back every month. Whatever applies to you!
Knowledge base: It can be useful if you make a lot of the same knowledge articles, with the same image and name. For example a knowledge base for HR processes, or an employee guide. Whatever applies to you!
Events: It can be useful if you make a lot of the same events, with the same image and name. For example an monthly update. Whatever applies to you!
See the following example of creating an Announcement. The process is the same for Knowledge articles and Events.
Insert template
So to make a template, click on: 
The following screen will be as shown below:
Now you can enter a title, insert an image, video or embed code by choice.
Image
Inserting image:
Video
Inserting video:
Embed code
You can embed a form within an announcement. This requires the embed code of a Microsoft Forms form.
When editing the announcement, add a Grid element and choose Video, which will allow you to submit an embed code
Copy the embed code of the form
In the embed code, replace "max-height:100vh" to "max-height:100%"
Paste the edited embed code in the Embed code screen of the announcement to embed the form
Inserting embed code:
Once you have saved the template, you can also edit it, rename it, duplicate it, or delete it later. Go to the template you want to change and select the three dots in the top right corner:
After clicking, the options will appear:
Just select the options you want to use; it speaks for itself.
Good luck!