The idea is to keep the log as close to your center of mass as possible. While you might get by with your method now, once the log starts to get heavy, you won't be able to hip thrust it up. Well...you might, but it's going to exhume a lot of energy and it definitely will not be the most conducive for getting a good rack position for the press. The most important and vital cue I've found it to shrug as hard as you can while the log is in your lap and on the way up. Mind you, you must keep your elbows up high for this. It's really just a squat and a very hard static shrug. Don't sweat not being able to catch on btw, it's easier to actually learn this technique with heavier weights.