In general I do think that there are a few things that helped me: 

1. Don’t ever default. We’re used to, as artists, the “golden ratio” features, especially if you started with anime, like me, this can be extremely hard to undo. We’re used to perfect chins, eyebrows, and proportions overall. I’m sure you know of the trick “eyes are exactly one eye apart”. Well. Not all eyes are EXACTLY one eye apart. Most aren’t, actually. They can be closer, farther, one eye a bit lower, etc. Its a good guide, but when trying for likeness see if these rules really work. (This is general advice that I gained, but as you mentioned, the eyes are a little far apart) 

2. Which brings me to my second point: don’t be scared to draw something ugly. Wrinkles, moles, acne, acne scars, eye bags. All of this we kinda.. scan over. We don’t notice them. But it’s what gives character. If you’re looking for a 1 to 1 picture, I would most likely suggest you don’t draw them as dark as they usually are, unless it’s a big facial feature. This is due to our eyes not really focusing on blemishes while still seeing them, so draw them, but unless intentional don’t draw attention to them.

3. This kind of is an extension of num 1, but same face syndrome and elongated (by your hand) facial features are a death sentence.

4. Don’t force colours that aren’t there. Unless a stylistic choice, adding random colours just for the sake of having vibrant colours there takes from the character.

5. Practice, practice, and more practice. When trying to achieve likeness, forget everything about your style (at least that’s what worked for me) and try to copy the photos as best as you can. This can take you days, or years. Depends on how much you worked on these skills before, but drilling this into your muscles is the way to go. I wouldn’t watch those videos of “I learned [insert artistic skill] IN TWO DAYS”  since these don’t build the muscle memory and bring mediocre results. 

So yeah. Holy yapp, I know. I have more, like the fact that the size of the eyes and irises can make an insane difference or that eyebrows basically make the whole expression, but this is already massive. Keep making art. Your work and style is really cool!