The goals of stepfamily living are 1) to create time and space for a strong couple bond to form and 2) to create a place for children to relate to all important adults. It's a game of chess, not checkers - at the very least irritating - complex not necessarily complicated. Shifting ex-spouse relationship to a co-parenting relationship, establishing limits and a space for parent/child relationships, creating an atmosphere in which children can comfortably and safely relate to all of the adults in their two families are important and difficult tasks.
Different histories, values, rules must be dealt with all at once. Blurred boundaries of the family exist because of the reality of children moving between two families and having emotional ties to other adults, living or dead. These realities constantly intrude on the new partner-child connection.
The social isolation produced by changes of residence or changes in life style have a major impact -loneliness- which is often ignored.
Communication skills have to be relearned in any new relationship. In stepfamilies one needs to learn to communicate with a new partner at the same time one is learning to communicate with unfamiliar children.
One needs to learn about negotiation and compromise, sensing that fine line between compromise and capitulation. For at least one adult in the stepfamily the previous relationship had a great deal of tension without love. For couples in stepfamilies there's now tension with love.
Learn that relationships are precious and that
everyone is unique.