c-x c-f"autocompletion for file names
A very nice trick with autocompletion is to press c-n c-p to havee a real-time filtering list an works with any kind of autocompletion. This is very useful when we have a lot of suggestions, e.g., like 20 or more suggestions and we may be confused with all that text, so in this case we can just press c-n c-p and type some text to filter.
For example, let's say we want to filter on some filename and we
are currently in a directory with a lot of files, we can do:
c-x c-f c-n c-p and this will allow us to keep the list and type
some text in order to have a better filter.