How to achieve glossy hair?

I know lighting/editing plays a role in some of these pictures, but how can I get something similar in real life? Preferably without heat. I have fine hair, and it’s pretty healthy, but I don’t think I could get mine to look like this in any lighting. Are hair gloss treatments worth it? Can you do this with just hair oil without weighing down fine hair? I have prom coming up this weekend, so I would appreciate any (reasonably priced) product recommendations!