Hello Anubha. Most collaborations, which are open to the public, are announced here on CakesDecor in the forum. Many collaborations are by invitation, but the hosts generally welcome anyone who would like to participate. If you have seen a collaboration which you particularly like, contact the host and find out if there will be a repeat next year, as many are. If so, ask to be added to the group.
Also, if you have friends who have participated in collaborations, let them know that you would like to join and they can introduce you to the hosts.
Sugar Sugar by SSmiley
