Be sure don't overtrain your statics, this exercise is quit exhausting for body and mind, especially the MAX attempts.
I only perform 1 or 2 max attempt a month, if I feel like it.
I focus on learning my body, try to feel what's it doing, trying to relax better, letting my mind go freely etc. For O2 I concentrate about the ammount of effort instead of the time. I do 4 or 5 breathholds in a training, on 50% second one 50% third one 70% fourth one 90% fith one 90%, where The percentage indicates the feeling when I come up. For instance 50% let me come up with FEELING that I could do twice as much.
I have my buddy record the times, and I hear them only after the whole schedule. I do not carry a watch in the water. My buddy counts down the 2 minute interval.
After 23 months I have the Idea that Freediving is like a growing proces, which cannot be forced by hard training. Hard training will only produce big or huge fallbacks (SBS, Static Burnout Syndrome, as a friend of me likes to call it), and takes much of the joys away. The joy is not in the numbers, it's in the heart.
Kars.