A neat tip to remember when making a special Seamless Tile that you'd like a certain area nicely and clearly preserved.
Bring in the use of our Selection Tool ...
The Fun Image below, has text in it that is lost when doing a regular
Bidirectional Tile so lets set about saving it.

This would be the result if we didn't use the Selection Tool.

1 Open your image to be tiled
2 Click on your Freehand Selection Tool and use the same settings as I have - Freehand - Add(Shift) and Feather on 6 (Feather can be adjusted according to the size of your Image)
You can also use Point to Point for your selection if you're more comfortable with this Tool.

4 Hold down your left mouse button and encircle the area that you wish to preserve ... in my case, the Text.
5 Go to Effects - Image Effects - Seamless Tiling. Use the default setting and click OK
6 Click Ctrl and D to deselect and you have your perfect Tile ready to save as a .jpg for future use.

The Focal Point needn't be just Text, it can be any area of your image that you don't wish to have blurred when Tiling ... have fun with you tiles.