1) Make a unique cachy name of your youtube channel so that one can easily remind your channel name & feel enjoy while talking or promoting your channel . If u create a
unique name, it will give advantage in seo terms and while searching your channel, it will easily appear in 1st search !! This necessary steps really works for increasing subscribers .
2) Make a slogan or theme song with your Youtube channel.You you can set slogan with your channel as well as theme song like jingle bell song. It will impact great on watchers for increasing subscribers.
3) Channel Profile Photo and Cover Photo also works or increase efficieny of popularity of channel and no. of subscribers. If a user give attention to these things, it will surely help you to gain subscribers.
4) Inserting necessary contacts or social media links in top right section of cover pic which is available in about section in mobile view is also important for youtuber as it gives medium to keep closely touch with subscribers which also indirectly help to increase subscribers.
5) If a youtuber, gain somehow 4000 hour watch time or 10K subscribers, then user must insert attractive and clicky thumbnail for getting more watch views minutes so that it helps to get more subscribers.
6) Carefully use of Youtube Anaylatics ( Studio ) is so important for setting your videos keywords and labels,title,description,location,live streaming and much more things which help to target your audience and automatically, it also become catalyst for increasing subscribers.
7) Sharing of videos by manually in social media like fb,twitter,whatsapp,google plus,linkedin,pinterest,tumblr or in target based audience like if someone make videos on sports then user should spread his/her video links in sports lover zone or in sports fb group,google plus group, sports hashtag, or get backlink from sports website etc. It will help to increase subscribers surely !!
8) Second last way is your type of content,editing effect,topic which u decide to make videos on that. If you think your video has large watchers audience then u should carefully make videos and improve everything on video so that your can easily gets name,fame and subscribers for your effort.
9) Last one is Promotion Techniques –