You can ALT-Click the button parameter button (on the right side of the effect editor) and that will reset just that parameter to default values. You can also save the effect and drag the saved effect into any of the parameters on any new effects you apply. Example, lets say you have a 3D warp effect where you have the image cropped a ceratin way you like…save this effect…then if you apply another 3D warp effect to a different clip you can drap the saved effect right into the crop parameter area and it will crop the new clip just like the first.
Hope that helps