How do I patch ceiling cracks?

Hi Barbara, USE SOMETHING LIKE POLYFILLA WITH SAND ADDED TO GIVE THE LOOK, THEN REPAINT.

Hi. Sand a wider area so you can get to the cracks. Patch with exterior spackling that has more give in it than interior spackling. After all the cracks are patched and sanded smooth, repaint the entire ceiling. In the sanded areas, add a handful of sand to the paint and paint those areas. If it's the large "sand" type, you may need to buy the "sand" material at the paint store (sometimes it's polymer crystals, sometimes styrofoam balls). Done!

Oh how ugly...and as you say..very 70's ...if that's not the look you're going for then skimming the ceiling [a very thin layer of spackle/plaster] or overboarding and re plastering would be the way to go.

My suggestion would be to purchase 4'x8' beaded board panels and install them on the ceiling, then run strips of wood over the seams, creating areas that look boxed in. It will completely transform the space and then the crack issue will never be seen again!