As for something you can personally do to help your channel, I would recommend trying
TubeToolbox.
This is a program that automates certain tasks with YouTube like sending messages, and it IS legit. If you use it properly, you will get genuine subscribers that are interested in your videos and your views will definitely increase. Of course, this all depends on how interesting your videos are to your target audience.
It's not a free program, but it looks like at the moment you can try it for a week for $2. I bought a subscription a while back. I've only used it twice but it gave me hundreds of hits and a healthy dose of subscribers.
This is how it works:
You tell the program which videos on YouTube have similar content to you, (or you tell it which videos have the kind of viewers you are after) and it will make a list of all the users that have
commented on those videos.
So essentially it's making a list of people that would likely be interested in your videos.
Then it lets you send a message to those viewers and attach one of your videos. You just write a message saying something like "Hi, if you're interested in ______ then please check out this video. If this is not for you, please ignore this message!" Of course, you can promote your video a bit in the message to make it sound attractive (don't lie!), but be mindful that not everyone wants to receive such messages, so be polite.
TubeToolbox will then automatically send the message to the people on your targeted list. In order to comply with YouTube it will only send a certain amount of messages per hour (I think it's about 30 messages an hour).
I just let it run day and night for about 3 days and watched my inbox grow with new subscibers and comments. Again the reason its effective is because you're targeting people that are *already* interested in your type of video. This program just helps you get the exposure to that audience. If you use it wisely, I don't believe it's any more 'spammy' than posting your video on a forum dedicated to your particular interest. Except with TubeToolbox your video gets exposed to a lot more like-minded people.
I actually had people thank me for sending them a message. And I had people tell me to F-off. The majority of people were fine, but about 5% were really rude. So be prepared for some jerks that can't simply delete your message and move on.
As I say, I've only used it twice. I don't want to abuse it and lose respect from my viewers. But once or twice when you really need a boost it can certainly help. Especially when its so difficult these days to stand out in the YouTube crowd.