Stop trying to grab subscribers, and start providing valuable, searchable quality content that people want. Honestly you're asking the wrong question. The proper question is, "How to I provide more value? How do I know the videos I make are worth watching? How do I go about helping people changing their lives."
The fact that you're asking about grabbing subscribers tells me that you're really interested in your own pursuits than helping other people. Other viewers will pick up on that faster the speed of sound. Once they realize you're in it for yourself, they'll stay away like the plague.
So, in other words, it isn't about grabbing subscribers. It about providing so much value that they can't do anything but subscribe. Subscribers come as a side effect of provide excellent and valuable content.