Complex sentence: In honor of Grist's contributions to the field, the organizers of Twist & Shout, the biggest balloon twisting convention, instituted the "David Grist Memorial Award", now considered to be the life time achievement award for balloon twisters.
Split into simpler sentences: In honor of David Grist's contributions to the field of balloon twisting, the organizers of Twist & Shout, the biggest balloon twisting convention, instituted the "David Grist Memorial Award". The David Grist Memorial Award is considered to be the life time achievement award for balloon twisters.