What can I build in my minecraft survival world?

I'm out of ideas for things to build in my minecraft world. I've looked around on some minecraft forums and I can't find anything. I've built an animal farm with every animal, a crop farm with carrots wheat potatoes watermelon sugarcane cactus and even coco beans. I have a house, a nether portal, I've beaten the dragon in the end, xp farm, a beacon, a nether wart farm, a villager love shack and a villager house and a greenhouse and a strip mine too. I like to build things that are useful not just like a giant statute. Although any ideas are appreciated.