Do something no other youtuber has done. It is so unoriginal when you see "Pepper challenge () special" or QandA, Omegle, or anything of a sort. Make something nobody has seen before. Doing such simple things won't feel so special to your subs and many people will ignore it if not original. Giveaways are sometimes great but only a set amount of your subs get anything from it, the rest just see nothing special. Take Ryan Higa's videos for example. Each one is thought out marvelously and are genius. Do something that nobody would expect.