Easy may not be the best way to look at your ability to get ppl to subscribe to you. The goal of a creator should not be about gaining subscribers but about finding viewers who are looking for the kind of content you create. While I understand that gaining subscribers is basically every content creator's goal on Youtube, not to mention all the rewards YouTube gives for gaining subscribers, your main goal should be to provide quality content first. You should also focus on subscribers who want to watch your videos. Many creators focus too much on the number of subs they get and then wonder why they have so many subs but so few views not understanding that anyone can sub a channel but only those interested in your content will watch it thus you want to make sure those who subscribe also want to watch your content, that way your views can be greater.