I've moved this to youtube strategies because this is a strategies question.
the "easiest" and "fastest" way to get subscribers, is to make content that people find informative. Good thumbnails, good SEO (Search engine optimisation) and a compelling title will help your chances.
I find the best way to get subscribers is to not seem too desperate to want subscribers. Nothing puts people off more than someone too desperate for subscribers. You simply want to be helpful, entertaining and natural.
Also, you have to make 100 videos.
It usually takes 100 videos, and sometimes several months, or even years, to get "lots" of subscribers.
At the end of the day though, subscriber numbers mean nothing. It's what you give to others that will leave the real impact.