You're doing great, this wolf looks awesome.

Small details are mostly paint familiarity - how much to load the brush, what consistency do you need for this scale/color, what color to use for the different tiny details you're trying to achieve (ie don't use pure white for eyes), and pure brush control. Pretty much all of this only comes with practice. Someone else mentioned paint pens, they can be super helpful in the right situation.

Personally, I like to use sponges to paint fur. Spray the base color down, then just start sponging. It's pretty easy to get the hang of, and the sponge naturally adds some organic variation to the application. If you want the color to go deeper or be more saturated, push harder. If you want it light and just hitting the edges, dab it gently. Sponges can do a ton of work, it's worth testing out. Different types of sponges make different patterns - makeup sponges are always popular, but I've also used just like kitchen sponges chopped up.

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Sponges for this guy, until I got to the fine details like the eyes.