I've got a very active and busy mind. Lately, I've been having difficulty concentrating/ visualizing. Should I remove some of the power meditations in favor of concentration exercises? I have no problem feeling the effects of some meditations, but I feel that concentrating is my biggest weak point. Also I didn't really take the time to truly master some of the beginner meditations and skipped to the intermediate/advanced stuff. Not to sure what I should do. Sometimes, especially of late, my meditation sessions are either perfect or shit, leaning more towards the latter.