In the US at least, the usual expression is "bring it up A notch." This means to improve something a little bit. A "notch" is a groove or indentation in which something can rest. For example, the legs on some desks have a series of notches or holes, and the legs an be raised or lowered by sliding a pin into the notch/hole at the desired height. If you move the leg up just one notch, you are making the leg just a little higher.

to "take it up a notch" also means to try harder to to make something more exciting or interesting...