Like other edits, applying multiple effects is cumulative. Unless that's what you're trying to achieve, click the Undo button at the bottom of the Effects tab to remove the most recently applied effect before applying a new one.
You can apply one photo's edits to another photo. Select the edited photo and choose Edit > Copy All Effects. Select the target photo and choose Edit > Paste All Effects.
Many digital cameras provide settings that let you shoot sepia-toned or black-and-white photos.
Tint p. 84
Use Tint sparingly. There are few non-artistic instances in which photos look good with an overall bluish or reddish cast.
To create a duotone photo with Tint, move the Color Preservation slider all the way to the left.
When applying effects such as Tint, the process isn't necessarily as straightforward as "Do A, do B, and click Apply." You're free to select a color and adjust controls in whatever order works for you, as well as to repeatedly switch back and forth between these processes as needed.
Saturation p. 86
If too much Saturation is applied, areas of the photo will look blotchy. Move the Amount slider slightly to the left if this occurs.
Soft Focus p. 88
If you apply Soft Focus to the elements closest to the camera, you can simulate depth of field. This is an excellent way to attain more natural-looking photos from fixed-focus cameras that are focused for infinity.