Sunset

I know there has been a thread about this, but I can't find it here. I need some tips on shooting a couple in front of a sunset. I want to be able to see the sunet, but I would also like the couple to be properly exposed. Tips? Please?

Some fill flash might help - if the sunset is behind them you need some kind of lighting for their front, whatever the means (big reflector perhaps?).

I have a 430ex, will that do? do I need to under or over expose, or what?

If you can keep the subject completely still you can try a slow sinc to light the subject and the long exposure will have the great colors of the sunset

Generally, take a reading of the sunset without including the sun in the frame. That's your base exposure.
Then adjust your shutter speed to keep that equivalent reading, like 1/200 @ f/8, or 1/100 @ f/11, etc., while...
Then adjust the flash to give the "right" amount of light at that base exposure. Either by putting it on "M" (my choice), or whatever works with your set-up.

Here's an example of my results: Fill light at sunset, which BTW, is in
Studio Lighting Set-Up Links –illustrations of real world examples.