A good way to do so is to actively be kind and encouraging on peoples' skins. That gets them to meet you and they might check out your profile. Especially if there are other people subbed to them, so they might check your profile out as well. Another thing is to just keep skinning. The more skins you have, the more people you'll attract. (Especially if it's a popular character, such as a Smash Bros fighter, Undertale, FNaF, popular cartoon characters, etc.) Not saying you must make popular characters, as you can do whatever you like. Just another way to gain subs. However if you're uncomfortable with that particular thing, another way is to find people with similar interests as you. They will support you for what feels like forever! Then when their followers discover you, they'll check you out. Another thing is just plain making awesome skins. I can tell you're going to gain many followers since you make awesome content and rather popular characters as well. It is a slow process, but man does it feel awesome.