You need to:
- Shoot interesting content that is engaging.
- Have good thumbnails as you are competing against everyone else.
-Do keyword research using adwords for your tags, description and titles.
-Either create a new piece of content or speak / do something that is a popular topic.
-Good branding- channel art, channel trailer & icon. Stand out be and be unique.
-Promote- find areas to share your content.
-Stick to a content schedule and tell your viewers why they should subscribe also this will make you more favourable in YouTube's algorithm.
-Call to actions- ask your subscribers to like comment and subscribe- they might forget!
-Keep motivated, can take people a year or more to get more than 100 subs, just have to keep grinding and create- we don't create for popularity, we create because we enjoy it!
- If you can collaborate with other channels, anyone that is big on YouTube has done this so this will help a bunch!
I have done these tips on my channel currently doing pretty well- check out my channel for an example