This stuff seems pretty neat. I do work on Photoshop too but it's more based around a grunge style. I don't have the artistic vocabulary to go into detail with your work but i wont leave "nice work keep it up" as a response or whatever so bare with me. The First picture draws me in the most because of the slighty saturated color pallet. The symbolism on the shapes is really neat, somehow i'm able to tell what's what without it being to distorted or too dull. The signature picture looks pretty cool too, although i would advise you add a little more variety of patterns in the background , there a a few plain spots that i noticed after awhile , other than that the color pallet to work well and the line work gives it a crisp feel to it. The Christmas card is a W.I.P so i'll be a little more empathetic due to the progress of it but to be honest it seems a little to simplistic. Other than that there's not really much to say about the final picture some stand out more than other but that's about it.
