Say I'm training a model for multiple tasks by trying to minimize sum of losses $L_1 + L_2$ via gradient descent.
If these losses are on a different scale, the one whose range is greater will dominate the optimization. I'm currently trying to fix this problem by introducing a hyperparameter $\lambda$, and trying to bring these losses to the same scale by tuning it, i.e., I try to minimize $L_1 +\lambda \cdot L_2$ where $\lambda > 0 $.
However, I'm not sure if this is a good approach. In short, what are some strategies to deal with losses having different scales when doing multi-task learning? I'm particularly interested in deep learning scenarios.