Hit the right spots. The throat is perhaps the best place to start as your body heat is closest to the surface and most likely to intensify the cologne.
Spray enough so that people know you're there, not so much that people know you're coming.
Reapply after long periods of time. If you applied cologne in the morning, reapply in mid-afternoon.
A person's sense of smell is not as acute in the morning as it is later in the day - so when applying in the morning, splash carefully.
Citrus and aqua are great daytime fragrances while sandalwood and musk work well for nights.
Baths are no substitute for cologne. And if you fail to acknowledge that, remember that social rejection will make you.