How to Manually Monetize a Video
When you are uploading a video, there will be several tabs underneath the video preview that you can view. If you click on Monetization, it will show you a page where you have the option to monetize the video.
As you can see in the above image, the monetize icon on the right hand side is greyed out which indicates that the video is currently unmonetized. To monetize the video, you must change the Usage Policy to "Monetize in all countries".
Once you check the box, notice that the Monetization icon turns green. After choosing to monetize it, you can change a few of the settings as seen above. Once you have configured the settings to your desires, click save and your video will now be monetized!
From your video manager page, you can easily see which of your uploads have been monetized and which haven't as indicated by the green or grey monetize icons.