The tutorial you followed isn't very good, it obviously didn't explain a very lot.
The text is horrible and is way too big.
The render, really you always want to try and disguise and it into the background so it all flows together.
Try to check other signatures and look for better tutorials, some are really easy.
Try this one - http://xicegfx.deviantart.com/art/Si...orial-54331213
It's nice and is explained, maybe some stuff isn't like how to set blending modes.
Give it a try!