Top-down hats

I'm trying to start a hat, using the top down no swatch method. With very bulky yarn, it seems that the difficulty lies in getting off to a good start without a hole in the top. Supposedly, if you use Emily Oecker's method of casting on, you end up with a loop of yarn whose tail can be pulled to tighten everything up. It hasn't worked for me so far. Maybe I should practice with something other than a double strand of slightly lumpy cotton...