Some notes about this photo:
Location: Rizal Park, just below the bridge. The Jose Rizal Bridge is one of the most popular spots to get the Seattle skyline, but that bridge vibrates every time a large vehicle drives over it. Not great for longer exposures. I recommend walking south a bit to find the the Rizal Dog Park entrance. From there, walk downhill to the dog park and find the exit to the paved path below. The view from that area doesn't include the port and sports arenas, but the ground is much more stable if shooting at night.
Shooting/Post Processing tips and tricks: Sunset pictures with well-lit foregrounds are hard to nail-down in one exposure because the sky doesn't really come alive until a few minutes after the sun has already set. For this image, I took three exposures: one during the golden hour to get a well-lit city for some depth in the skyline, another exposed for the sky at its reddest moment just after sunset, and a final photo after dark to get the city lights. Each image was processed in Lightroom and blended together with a bit of creative masking and blending in Photoshop. Try using the "Lighten" blend mode for the darker photo with the city lights.