First of all, it looks great! 3/4 portraits usually are the most difficult and you did a good job. I haven't worked that much with water colours, but a thing that catches my eye is that the washes aren't done that clean, which is probably why there are these lines where the colours haven't properly bled into each other. From what I remember, you either have to wait until the layers are fully dried up or you have to add the transitioning colour, while the paper is still wet. It would be helpful to try it out on a seperate piece of paper. Also, never forget to add the light of life to the eyes. This makes the person look more alive, as the name says :) That is all I can see right now. I hope this might help. Cheers!