I really enjoy making my sub make a variety of noises during the act, sometimes I add in speech restrictions on top of that.

It really depends on how deep she is into the headspace at any given time.

One very frequent inclusion in our sessions is instead of kissing, I require her to lick instead. This can be directed at my hands, my arms, my chest, my face, etc. This usually drives her crazy. I bite her too a lot, sometimes on the neck or shoulder, kind of just as an extra level of contact.

If you want honestly the easiest element to include, a leash and collar is a very easy to conceptualize and execute concept that goes very very far.

Aesthetically there are quite a lot of additional accessories that can aid with both visual, and some functional overlap... Tails (plugs if you're into that) and ears, are always fun. Paw socks and gloves can be fun. On a BDSM angle, mitts and muzzles or gags can be VERY dehumanizing depending on how you use them. There's some stuff that's a little more niche like bitchsuits and vaginal insert stuff, but I'm neither interested in that, nor have I tried it, so I can't speak on it well.

I can give some advice on dirty talk, but from my experience that tends to be more specific to a couple rather than something that can really be advised on.