I must ask you something before: have you decided a precise "road" where your style should lead to?
I'll explain why I asked so. Your style looks like a mixture between a more "comic" or at least "creative" style and a photorealistic one. Which isn't bad at all. This is a good example of the "creative" side, versus Attempts to go after a more definite realism.
I think you should work on this mixture. It's a peculiarity of yours, and if studied and improved it can lead you to something not many "whoa wonderful" artists here can achieve: Being original.
I'll teach you an easy trick to see faults in your work: scan it and mirror it on screen. Prepare to panic. It's actually harder to see faults in your own works when the eye is "affectionate" to a precise set of shapes. Pausing from the work and looking back at it after some months could also do the trick: you'll immediately find a lot of things you want to tinker with and you actually have in mind how to improve them Mirroring or waiting some days only would be faster tho.
Hiya If you don't mind I'll help critique you, and perhaps give some suggestions. Now lets see, where to start.
Now overall, you have a good concept going on, and great shading. I would say two of your best portraits are of Scarlett Johansson and Zoe Carter. However, may I suggest practicing lips more? There are lip tutorials floating around the internet; practice makes perfect!
Ideas? How about some people of the past John Lennon, Jim Morrison, Freddie Mercury, the list could go on and on.
Thank you. I will look at some lip tutorials. They are pretty hard to draw, especially if the picture is not a high quality one. But I'm sure that with practice, even if the picture is not high quality, I will know how to draw them properly. Thanks.