Yes, there is a whole bunch of tricks for improving either AM or FM performance. However, most are impractical or heavy. Often you can improve reception simply by providing a better ground to the radio, and that might mean another piece of wire to Earth, or it might mean cupping your hand around the right part of the radio case.
In the UL sense, if you can't do it with five feet of fine wire, you won't ever do it.
What you won't do is to improve your GPS antenna reception much except by replacing the antenna. That, as they say, is a totally different ball of wax.