I have some super old signature tutorials you might want to give them a glimpse, i tried to be human when i wrote them, all of these are for Photoshop.
To master signature making one cannot simply ignore cut outs (or better known as "rendering"), for this i made the pen tool tutorial
After fiddling with the pen tool, basic filters are followed, the blur filter tutorial
might help you in that.
While this last tutorial
was done even before the above ones, it mixes different tools.
But if you were asking for someone to make them for you, there are a lot of pro's at DeviantArt and a scarce number of makers at Aeria forums fanart sections, navigate around in these forums and you might get to see some "signature shops" or in any other forum aeria has.