Applying a preset doesn’t necessarily mean that the editing process is over. It just makes your workflow faster and gives an idea of what the photo will finally look like. You can fine tune the photograph by adjusting the sliders on the right side of the window in Lightroom.
In landscape photos, make sure that the horizon is straight. For beach photos, you can refer to the sea level at the horizon to determine whether it is straight or not. If it’s not, use the angle tool in Lightroom to straighten the horizon.
If you’re not satisfied with some elements in the frame, crop the photo. When cropping an image, you can use the rule of thirds to make the composition even better.