It may be the hardest thing to have to do as far as subs, Keep up what you're doing and simply wait. If you already don't have a strong following on sites of choice, (I.E. Facebook, Reddit, twitter, pintrest, ect.) It may be just as hard getting likes and subs to those as you'll primarily be using them to advertise... and most of the time be brushed off as nothing... Simply wait, you're subs will come. This is the only sure fire way to get subs, continue content creation, and wait for your subs to trickle in.