A mirror can be created in many ways, here I have shown two of the ways to do it.

1. Create a new document of size 300×80

2. Select Type tool (T) and then write a text at the top of the document.
I chose a blue color and size 36px.

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3. Select the marquee tool (M) and drag a rectangle around the text closely, and then copy the selection (Ctrl + C).
Paste (Ctrl + In) so that you just copied and select the Move tool (In). Check that the top layer in the Layers palette is selected, and drag the text to the bottom of the document, so you have two similar texts together.

4. Go into Edit-Transform-Flip vertical, and then yank the text up a bit so it is just below the upper text.

Your image should look something like this:

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5. Then press the Add a layer style bottom of the Layers palette and select Gradient Overlay, click the Gradient.

Here click on the arrow in the lower left corner of the color and choose the same color as you have typed text.
In the lower right arrow, select white. Dialog box would then like to look like this:

gradient_editor1

click OK.

6. Put the Angle to -90 and click ok.

gradient_overlay

7. So we just put Opaticy top of the Layers palette to 50%.

Then we finished

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As I said, it could be done in many ways. Another way to do it where you can control the gradient a little more on my show now.

1. Follow the first four steps as shown above.

2. Low as a new layer by clicking Create a new layer (Shift + Ctrl + n) at the bottom of the Layers palette.

3. Select the Gradient tool (G) which, together with Paint Bucket tool in the tools. Check that the linear Gradient is selected in the top menu bar and click on the color of the mark.

4. Put that here both arrows at the bottom color to white, or otherwise, if your background has a different color. The arrow in the upper right corner enable you Opaticy to 0

gradient_editor2

7. With Gradient tool still selected you draw a line from the bottom of the bottom text up the middle in the top text.
Depending on how long you drag the sheet you can control the gradient to fit what you want.

8. So we just put opaticy to 75%.

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You can also use this method on more than one text, For example. images to be mirrored.

Then we finished.