More seaming woes

anyone know of an online resource for different seaming methods? I can do a mattress stitch fairly well thanks to the videos here, but I can only do that if it’s stockinette to stockinette. I have some seaming to do that will be like moss stitch to stockinette, moss to rib, etc. that I would like to be “invisible” like mattress and not sure how to go about doing it and not having luck googling (coming up with a lot of class schedules at LYS all over the country, maybe I’m searching badly.)

thanks a bunch!

Here’s a few. You have to scroll a bit on some.

Thanks so much!!!