Like Koala's, there are many tutorials on google on how to increase on your viewer/subscriber count. The overal message they are trying to get across is quality over quantity.
Its (in my opinion) far more important to have quality videos which are entertaining to watch then having a lot of videos with only a few funny/interesting parts. This is easier said then done and it might take some time editing/fixing your sound/video quality but it is definatly worth it.
Also note that you wont notice it instantly, growing is (99% of the time) a slow proces. Patience is your best guess here
Good luck!