For ages I couldn't manage to get a decent result with triple embossing, but now I think that I may have cracked it. This is what I do.
1. Cut out the shape of card to be embossed.
2. Stamp all over with clear Versamark ink.
3. Sprinkle embossing powder all over the card and shake off the excess.
4. Heat with a Heat gun until all the powder has melted.
5. Stamp again with Versamark and repeat stages 3&4.
6. I do a total of 4 layers of embossing powder to get a good finish.
7. On the final layer, when the embossing powder has become liquid and is still hot, press a stamp which has been inked with Versamark very firmly into the molten powder and hold for several seconds.
I think that it is also important to choose a stamp which has a definite line and is fairly deeply etched.
These instructions helped me... I hope that they may be of use to you too!
To get a close up, simply click on the image of the card!