O.K. So first of all, you need a themed channel, people who watch your videos will only subscribe if they think they are going to see a similar video to the one they. If they see a guy's channel witha video of his dog, then a video of mw2, then a video of his nintendo DS, then a video of him falling off a pony, they aren't going to enjoy every single one of these and will most likely not subscribe.

Secondly, originality is key. If you upload a tutorial on how to do a glitch, with about 50,000 videos showing the same thing, why are people going to even click on your video? If you upload a video of a turtle eating a potato, this is VERY original, never seen before, people wanna see this as they have NEVER seen it before. The first step to getting a subscriber, is getting them to watch your video, and this will help.

Next, Don't ask for subscribers, so many times I see videos saying "SUB PLS AND LIKE AND FAVOURITE AND COMMENT PLSSSSSS MAN MY DOG DIED". No. I would never subscribe to someone like that, you need to get people to susbcribe to you who want to, rather than who are forced to, otherwise they'd never watch your video? If I subscribed to someone, and they upload a video I would never want to watch, just because it's in the little subscription box, I ain't going to click it.

Now, you need to be good at what you do. Having an original idea is the start, for this example I'll use painting cars with vegetables. Fair enough very original, comic = subscribers. But if you take it over serious(which isn't funny) and you are bad at it(non-skilled), people will not enjoy the video, and won't subscribe, they'll probably dislike and post a bad comment. If you posted a very funny video of this, you being yourself, and the result was good(or very funny), then people are going to like it, post "hahha nice one " and possibly subscribe.

Don't lie & be yourself. If someone is like "Sub and I'll give you 15th prestige", even if it's a good video, I ain't going to lie. If it's a 10 year old white boy, and he's acting like a black gangsta, I ain't going to subscribe even if the video is good. If I see a normal kid, talking in a normal attitude about normal stuff, if the video is half-decent, I'll subscribe.