This neutral space can be creamy bokeh (which as we know is used a lot of portrait photography to let your subject stand out against the background) or open sky, grass, walls etc - anything that does not compete with the main subject for attention by being too "cluttered" and gives the viewer's eyes a chance to rest. Having negative space in your image can help sharply define and emphasise your main subject by drawing the viewers eyes directly to it.
Now that we know what Negative Space is, how do we use this in our photography?
Firstly, whether to have negative space or how much to use is a matter of personal style and is subjective - some photos work amazingly well with lots of negative space, others better with just a little "breathing space". If you follow the rules of thirds you will probably have your subject on one side of the frame, balanced by negative space on the other, however, in some cases, when breaking the rule of thirds works, you can have negative space on either side of your focal point - or have your subject take up just a tiny bit of the frame, filling the rest with negative space.
Here's some examples of negative space.....
This image has a lot of negative space - leaving my child Callum to stand out as the main subject. This does break the rule of thirds intentionally, and gives negative space on both sides of the subject. There is nothing to take your attention away from the main subject - the eye wanders around the frame before coming back to the main focal point.
This one has contrasting negative space - the background is black (I did clone out some lighter areas that were distracting) and therefore lets the subject stand out more.
Not the nicest photo of Callum (understatement!) but I'm sharing it to show how you can use negative space as an area for your subject to look into.
Another beach shot with some negative space - there is some areas of interest in the frame but not much, it's still "quiet" - there's not much for the viewer to land on. This image would have probably worked well with even more negative space, giving a bigger sense of how small the child is.
Please ignore my child's charming expression - I get this most days now when I pull the camera out, I think he feels it is his best form of defence. The background here has melted away into a creamy bokeh giving a neutral background - he is positioned on one side using the rule of thirds.
The same can apply for objects too, not just portraits - some negative space can help them stand out more.
When shooting, try to think as much about what you are leaving out of the picture, as much as what you are focusing on - experiment with negative space in your photographs, cropping differently to see how the inclusion or lack of negative space impacts how the final photograph turns out.
I'm quite "safe" with my use of negative space (although I'm keen to try to get more adventurous with it!) so I've started a pinterest board with some examples of the use of negative space in photography that you might want to check out if you would like to see some more.