So, I guess you want to learn to make overlays? First of all, you need to decide if you want to make the overlay soft or dark. Just read below, and you'll see the difference. I used the same gradient and pic for both, but you can tell that they're different. I suggest you read both first.
Soft Overlay
This is the most commont type. First, open up photoshop and open up your picture.
To see the full picture, click the picture and pull it to your adress bar
Okay, now create a new layer.
Now, pick a gradient to use on your picture
Put the gradient on your new layer, and then click overlay in the menu shown below.
And now, you're completed!
Dark Overlays
Like before, open up adobe and open up your photo.
Click on the background layer. If there isn't one, make a layer under the image. Now, color that layer with the gradient. Go back up to the top image and click on soft light.
