How to add shadow - and make as good as Photoshop

[enginestar]

In Photoshop...
I take an image, copy all...
Create a new image (with transparent background) that is 10 pixels bigger all around...
Paste the copied image.
Add a shadow all around the pasted layer - with zero distance and 5 pixels spread
Save as a PNG.

I've tried and tried doing the same in Gimp.
Grrr... no luck.
The shadows I get are pants Smile
Nowhere near as subtle as Photoshop.

I went back and looked at other videos...
These involved making masks and other things...
I'm happy to do that (if I have to)

My thoughts were: it's just such a basic task adding a shadow around an object...
Why is it sooo painful to do?
(Errr.... I'm guessing it's not painful at all and I've just not watched the right videos on youtube.)

Thanks.