Good try, choo! Like to share my comments (hope no offence)
#1, #2 - Nice shot, suggest putting more contrast that will make it better.
#3 - Overexposed :think:
#4 - Try focus first, lock focusing and then place the filter.
The softness might also be due to camera shake.
Even with Tripod, you could try using remote or timer to trigger the shutter.
I also realised that my camera strap also could cause the camera to shake
Now I use remote and also hold on to the strap when triggering :sweat: