The next part to drawing manga is, the expressions, there are lots, and everyone is unique, there are also different eyes. Look at the photo above for some inspiration ⬆️
Or type on Google to see more expressions: manga expressions and eyes
There is some shading involved in this like;some eyes are shaded.
If you don't know how t shade stuff, don't worry, it's an option.
To draw the eyebrows, make sure you leave enough amount of space between them.
Start with thick and as you get nearer towards the sides of the face, start to make them thinner.
And the eye lashes above have to be quite dark and the lashes have to be long and not straight but curved, and the ones below, have to be slightly shorter of course but just as curved.
The mouth I guess depends on which expression it is, but doesn't have to be very round and can simply just be a straight line, or slightly curved line.
If the manga expression is angry then draw some creases beside the eyes or on the forehead. So it's more realistic and when people see it, they will instantly know that it's an angry face.
If you want to see different examples, search on Google for the expressions.
Btw: you can tap on the photos above to see the full picture ;)