I agree.Advice that I could give that the others haven't is always try to do better everyday, not better than Cry, or pewds or whoever. Just better than the you the you were yesterday. More of a life lesson but really it applies to everything you will ever do.
Tell me more please about your experiences with preroll ads. How long are your ads? Is it similar to a channel trailer?But I would say my biggest tip to boost a new channel is to sign up for a adwords account using a voucher. When you spend $25 - adwords gives you $100 free credit. Wait until you have a few videos up, pick your best one and promote it. Make sure to set the ad to only run Pre-roll and set the bid to 0.01. Target the ad to only appear on specified URLs of videos you think will have a similar audience!