I’ve had long hair for about 20 years. Hair tie is number 1, in a pinch though I just grab a locke of hair and wrap it into a ponytail. For the last 6 or so years I’ve had dreadlocks and it’s about the same, but I have way longer dry and wash times lol.

Before dreadlocks though, I found that more oils and products I used the more my hair fell flat, so for about 6 or 7 years I did the no-poo method and my hair liked it quite a lot. My hair was very curly and full, and could pretty quickly tell when my hair had too much sebum and other oils building up

Not entirely sure how you’d go about getting slicked back hair that also isn’t flat etc, but from what I know of my hair, I would try a good deep clean and trying a small amount of pomade just at the roots/scalp. Seems like you’d most likely end up in a cycle of having to wash a lot though, but not really sure