Google has recently added a feature that makes search suggestions even more useful. Let's say you type [christmas shop] and then you realize that you wanted to search for [christmas tree shop]. You don't have to add the word "tree" to your query: just type "t" before "shop" and Google adjusts the suggestions. The first suggested query is [christmas tree shop].
The change may seem subtle, but I think it's really significant: Google takes into account the caret position and shows suggestions for the word you are currently typing.
Here's another way to use smart suggestions: type "cat" in the search box, then type "r" before "cat". The first suggestion is [ragdoll cat], a popular query starts with "r" and includes the word "cat".
Yet another reason to use Google's search box instead of typing a query in your browser's search box.