Complex sentence: Aside from his work as a musician, Mickelson is also a graphic designer and designed the artwork for the last three Borknagar albums, and is currently designing the artwork for Scariot's forth-coming full length.
Split into simpler sentences: Aside from his work as a musician, Mickelson is also a graphic designer. He designed the artwork for the last three Borknagar albums, and is currently designing the artwork for Scariot's forth-coming full length.