New to youtube, any advice?

"allharlowseve;c-16216297" wrote:
I'm All Harlow's Eve on Youtube and I'm currently restarting and rebranding my channel. I checked out your channel and it looks great. I've subbed! Everything looks amazing, the only thing I would watch out for would be the sizing of your thumbnail when you export it because some of them look off and have black bars. I know it's a very small thing (I didn't have much else to critique), but removing those black bars and keeping all your thumbnails looking clean and professional will really increase the likelihood of someone watching your videos. Hope it all works out for you!