All the luck to you from me.
I've always found horns to be so so SO hard to draw, especially to get them symmetrical. What do you do to pull that off? :)

Luckily just about nothing in nature is symmetrical, so if I were you I wouldn't worry about that!
For this I looked a photo reference, I've honestly been using Pinterest more than google, getty or corbis for my reference images lately, and I looked at the tines and said okay, this chunk of antler has this many tines, and the this one is bigger than that, and that one is smaller still...and just sort of made it be close enough. In the reference picture I didn't like how far out the lowest back tine stuck out, so I shortened it to my liking so it would stay with the general curve of the design. You don't have to make it right, just make it look right. You're not creating antlers, you're creating the thought of antlers, a representation.
If you're drawing something you want to be symmetrical I'd recommend using tracing paper and folding the drawing in half. I do a lot of my drawings on tracing paper because it's sort of a poor man's photoshop. It allows you to redraw and move around and add on without much effort or commitment.
I usually do a rough sketch in a regular sketch book, then when it's ready to be inked (like this) I lay higher quality tracing paper (don't go for the cheap stuff, it's maddening) over and trace it in pencil, then ink that. That way I still have to original and don't have to worry about botching the inking.

I also spend way too much time looking at reference pictures, and of course repetition. Practice makes perfect! For every good thing I do there's at least five sub par drawings that never see the light of day.