You may or may not know, when your in the mini-buffer, you can use Tab to finish your input.
Emacs will try to guess what your after and offer a few suggestions. If your trying to load a file from your home dir, you can do:
Ctrl-x Ctrl-f Start-of-Filename Tab
As long as the file name is unique, Emacs will open it for you. If its not unique, Emacs will open a buffer and display your options. Then you can either type more characters to identify the file you want, or mouse select it (boo hiss - don't use the mouse). If you can stick to the keyboard, you'll be way faster and more productive.
Give it a try.