Am I Doing Kriya Wrong?

[Butters]

I haven't studied it. I don't have access to the book where I am right now (traveling). 

My main source has been this guided meditation 

At first I found the effects quite strong. I would stop early for that reason. But now when I do it in bed it's not that strong anymore.

What are the desired effects of doing this? Should it feel mild or strong? Do you do it at set times or throughout the day?