shiny diagonal Edges

Same technique as in the previous tutorial, but with a different 'Shape', 'Repeat' and a simple 2-color gradient. Then Colour-Curves.

You could do this with the layerfx 'Gradient Overlay' and get very precise results, because you can always preview and tweak the values until you are 100% happy. The problem is: it will give you jaggy edges.

As a workaround to this problem, you could make a rectangular selection around the text, fill it with any colour (green) on a new transparent layer. Then make another selection from the text and fill the rectangle with a different colour so you can see the edges of the text (orange).

With that helper-object as your base, apply the layerfx 'Gradient Overlay', and finish your Stroke with a layermask.

First type in the center coordinates, which are half the canvas size.
Then set the 'Repeat' mode to 'Triangular Wave' so the gradient reflects on repeat.
Next set an angle value that you like.

Finally check the 'Preview' button and live edit the 'Width' until you are happy.

Update 2019

I noticed interest in this post and had another look at the tutorial.

In 2013 i was all about translating Photoshop layer effects into Gimp. There were loads of useful lessons to be learned, especially the whole Contour/Alpha-curve thing was such a revelation.
But looking back its also clear, that Photoshop did quite a few things right and Gimp didnt.
You just cant beat the live-editable layer effects of PS.

To this very day the Jonathan Stipe emulation of layerfx is the best we have, but it was always a buggy plug-in.
I dont know which version of layerfx i used for this particular tutorial, but i noticed that you can actually apply the 'Gradient Overlay' effect to your text without getting jaggy edges. So maybe that issue got fixed.

I still think the tutorial is useful as it demonstrates how to get the shiny edges effect with the 'Gradient Overlay', although if i had to write a new one, i would do a few things differently.

Plus, the Gradient Tool has improved in version 2.10 with its new live editing capability.
Its still not as flexible as PS, but we are getting there.