Yes! Just write some nice comments and interact with people. Preferably people who make similar content to you. They might check out your channel and if they like it, even subscribe. But don't even mention your channel! Or people will most likely get annoyed. Or even worse, your comment might end up in the spam filter...
If they like your comment, they may check out your channel. And if they like your channel, they might subscribe. That's all!
Youtube Tip!
Thumbnails are VERY important! Try to make them look as nice as possible. If your video has a boring thumbnail, less people will click on it. Even if it's amazing!