I like half-square triangles. I have made them in may sizes and can arrange them in so many different ways. I have never gotten bored. The end result can be very traditional or modern. I have a simple black and white sheet with about 30 ideas for blocks that use HDT, but can't find its link.(Grrrrr) But I did locate a site that has some good illustrations,
https://www.sewwhatalicia.com/half-square-triangles/