This sugar skull tracing page has a few fun details for the kids to trace over. Younger children can trace in the channels; older kids can trace on the dotted lines.
Trace over the dotted lines to make a pretty marigold - or just a generic flower - read to be coloured in. Marigolds are used for decoration in Mexico's Day of the Dead festival.
This lovely, decorated owl face was originally designed for Day of the Dead, but I think the kids would enjoy tracing over the dotted lines and colouring in some of the details at any time of year.