Using an electric shaver, I like to shave before a shower (in the mornings). The little bit of oil on my face seems to help keep the shave smooth and keep it pretty close. If I use the electric after the shower, it doesn't quite do the job I want.
However, when using a blade (haven't done so in a while), I like using it after the shower since my face has most of the oil and dirt removed, while still being soft for the razor to get close. Sometimes I do both and it comes out extra smooth.
vash