Stream management is very personal and will vary from person to person, and company to company.
But if your Google Plus stream sometimes feeling like a torrent of information flowing from individuals, communities and Pages then here are a few tips for you... Before we begin let's look at where the content comes from that appears in your stream...

The sources of stream content

These are several main sources:

1. Your Google Circles
2. Communities to which you belong
3. What's Hot and Recommended
4. The +1/recommends from people within your circles
5. Your own posts

Here is a video that gives you my approach to this:

Why take a look at this?

As an individual, or a Page, once you get your settings as you want them you will be able to much better manage the flow of content.
As a business this will also really help you understand how people 'see your content' in their streams, and hopefully make a splash!

The process:

So, in order to manage the content you see, let's look first at the top 3 listed above.

1. Starting with your circles

In the case below, you can see:

1. a Circle called ‘Notify’

2. more circles on your Home Page by clicking on ‘More’ (recap)

You can decide on the volume of content you get in your Home Stream by choosing a circle (i.e. clicking from this page) and:

1. If you want to receive notifications (from any of your Circles ) ensure that the bell is switched on

2. Choose if posts even appear in the Home Stream (if they don’t you are less likely to see them) - uncheck the box that says "show posts in the home stream” to prevent the content from that circle appearing in your Home Stream

3.Choose the volume in your home stream if you choose to have that content appear (by checking the box in ‘2’).

Note: for each of your Circles, you can then decide how much content you want to be seeing in your home stream, whether it's more, standard, or fewer amount of posts.

When you do this on each Circle, you'll find you're controlling the flow of content in your home stream.

Adding someone to a circle straight from a circle’s page

If you want to add an individual to the particular Circle, then by going to the stream of that Circle, you can just add a name and that will be added to that particular Circle's list.

If you want to remove an individual, you can always hover over and then just remove them or put them into a different Circle.

Size of circles and dealing with old circles

The larger the circle size the less likely you will be able to email the person i.e. you will have to rely on notifications within Google+. As such consider the following:

What size does the circle need to be?

Would it be more ‘useful’ if there were several smaller, more niche circles?

Are there any old circles I can now delete to keep my circles tidier?

Note: if you delete a circle and you have already ‘shared’ it either publicly or privately, that post (with that circle) still exists even if you delete it within your circles. If you want to delete that circle from the post, you will have to delete the post itself.
Tip: when you first share a circle, consider locking your posts if you think you may not want people to be sharing ‘old’ contacts.

2. Communities

Now you get the general idea, you can apply the same principle to communities:

1. Click on the cog

2. Select the volume for that specific community

Volume of content in stream from Communities

3. What's Hot and Recommended

You can apply exactly the same principles to What's Hot and Recommended:

1. Click on the cog
2. Select the volume

Volume of content in Stream from What's Hot

4. Posts may appear when people from within your circles +1 them

Here is a post dedicated to this subject: +1s/recommend article but the short version is, you may receive recommendation from people in your circles when they +1 a post.

5. Your own posts

When you post your own content it will appear, including when you share content. You may also see the content 'jump' back to the top of the stream when people comment on theses posts.

Those five things combined will determine the flow within your stream.