Check out this video for a full overview!
Depending on the situation, both methods can be very useful. Here are steps for both methods
Method 1 - Start from Scratch
Step 1
Go to the Streams section and scroll until you see the Shared streams section. Then click on the plus bottom
Step 2
You will then be prompted to create a stream as usual. There is just an extra step to add the people who you would like to share the stream with
Method 2 - Convert a Private Stream into a Shared Stream
Step 1
To create a shared stream, you first need to create a private stream to share. In the Streams section click on the plus button next to the Private streams.
Step 2
Finish setting up your stream
Step 3
Click on the Share button
Step 4
Add the names/emails of the people who you would like to share the stream with.
Step 5
Find your shared stream in the Shared section