Tips for certain upper body exercises?

When it comes to working my upper body, there are two exercises with which I never seem to have any progress: reverse flys and lateral/ventral raises. For all other exercises I can bump up my weight from time to time. But for these two exercises it seems impossible. It becomes a bit frustrating.

Does anyone of you experience the same? Do you happen to have any tips on how to make some progress? Thanks in advance!