I had/have a similar problem and have found that it’s not actually anything I do while taking the bearing but instead the initial direction I head exiting the control. Because I have taken so many bearings I know what it feels like to go straight vs curve. So if I exit poorly I tend to stay on that exit line cause it feels right to go straight. It takes me significant extra effort to realize I am off my bearing and curve back. Not sure if your issue is similar but may want to think about that exit.
Also sighting bearings I think is the best skill for compass bearings. Being able to just pick a tree and run is so quick and accurate. If you can make it second nature you can really just fly.