How are Grandparents thanked for the Christmas presents they give to their Grandchildren? I was always taught to say thank you nicely. I taught my children to thank the Grandparents nicely, even when they were given things they would never chose to have in a million years. For example, when dd 1 was 5 the dh's parents sent dd a hideous dress. Dd cried when she opened it. However, I spoke to her about thanking nicely and said when we saw the Gp's she should wear the dress and thank them. She did this and the dress disappeared like magic after the visit to the gp's, never to be seen in our house again. Over the years my dd's would put the hideous garments on, say they loved the awful plastic toys, thank the gp's for the terrible cheap toiletries. In short, we all made the right noises. Of course, their ds always got great presents from them.
I still practice the same now whenever I am given a totally weird gift.
We do, however, ask the parents before getting presents for our grandchildren as I don't want to put them through the same disappointment and charade as my dd's and I went through.