Never try to fill a hole larger than a corner.
Never go over the area more than 3 times… you will only end up pulling the mud from the edges. Splotch it into the hold. Feather from top corner to lower corner (reverse and repeat)

You can ad thin layers to fill in the imperfect areas. Use topping. They make sets that dry in 20 min, 40min, 90 min. Longer the stronger the bond. You want strong bonds on ceilings.

Check the wall after you sand it for even level feathering. Use a Level drag it across the area marking the high spots.

Its not hard if you take time to do it. You will get better the more you do it. I don’t even have to go over any of my work anymore.

anyways.. Have a good day.. don’t beat yourself up.

I tried to con the wife into doing it… “It’s just like frosting a cake.” Yeah. she saw through that lie in about .2 after she got started.