My meditation is getting better but...

[orion199317]

It seems like the less complex meditations I try the harder it is to concentrate. For example I know it may have been a bad idea but I tryed a few advanced meditations like the single serpant and it came easy to me. The visualizing of the serpant actualy moving and lighting up my chakras on it's way up cleared my mind and I was able to do it! But when I try anything geared towards a beginner I just can't concentrate enough to finish. What does this mean?
And is it safe?

Hail Satan