Color film... so your camera is automatic... problems?... the meter is only as smart as the person aiming it. Auto cameras have matrix and/or spot metering. If you are aiming the meter spot at a predominately very bright area, it will adjust the shutter speed n aperture acordingly to be stoped down and fast causing the negatives to be underexposed. Just the oposite happens if you are shooting, or rather, aiming the meter spot at a dark part of your subject.
Now that you are more concious of how your meter works, make it an effort to "see" what your meter is looking at. The view in auto cameras' finders generally have a small center spot or a series of matrix spots or squares, the areas your meter "sees" when it takes it's readings. Aim these markings at an area that will encompass a balance of darks n lights, or if it's a spot metering system, something of a neutral mid tone.
Another photo helper is a polarizer filter. It tends to boost colors and contrast a bit, but is only effective when you are shooting at right angles to the suns' direction.
Can you post some of your work? I'll bet your compositions are beautiful.