This year my nephews made it easy for me to make them toys for Christmas. At Thanksgiving, my six-year-old nephew pulled me aside and let me know with great earnestness that he did not have nearly enough Greeks and Trojans to have a proper war. So that was easy, another score of Greeks and Trojans and he was taken care of.
My eleven-year-old nephew had been asking me lots of questions about Medieval catapults and siege-engines. I made him a working model of a Trebuchet, complete with several different length throwing arms and slings. He had a delightful time out on their porch flinging things at other things (It is worth pointing out that the Greeks and Trojans make terrific targets).
My niece provided me with more of a challenge. Whenever I put out feelers about what she might want for Christmas, she was very vague in her responses. Without much to go on, I fell back on two reliable interests; she loves horses, and bears (see the whole bear thing post). She also likes to work on things, rather than just play with them, so what I came up with was this: a traditional, horse-drawn caravan, driven by, and occupied by bears.
I put my efforts into the caravan itself, the bears, and the horse and carriage tack, leaving much of the interior details unfinished. Instead of finishing out the interior, I gave her a box of raw materials to complete the bear caravan to her own design. The round top of the caravan slides off so that it is easy to get at the inside. She was already planning what she was going to do with it, including more bears, on Christmas day.