One of the distinctive features of Google+ is that it lets you disable comments and lock down posts from sharing, but so far, you were only able to do it after you share a post.
Now, you can do it before you share, which makes much more sense; after all, if you don't want anyone to comment on or share your post, you probably want it that way from the start.
You can choose the lock and disable options as you hover over the share box of an item you want to share. Check out how it works in the video below.