Struggle with retopology of my model

after a few lessons from cgcookie, I decided to go for a little more ambitious project to slowly start building my portfolio, and I took to make a sci-fi helmet model based on one of the lessons from the cg cookie.

I am struggling with the retopology of my model, I have the impression of doing something wrong in the early stages and now I have huge problems with retopology. Did I make a mistake somewhere or Im just weak at doing retopology? I not use any addon, I do everything manually when it comes to retopologies. (Sorry for my English)

Link to model

I am not seeing anything fundamental wrong on the model, but i am also not doing a lot of Retopo.
There is some pinching right next to the “ear”, because you have loops a little too close together, but other than that it looks good for a start.
You might want to look at the Retopoflow addon as it makes the workflow much easier than using vanilla Blender for it.

Retopology is a personal preference and less of a science and heavy on the art - that said, I do agree with Romanji about retopoflow, but for hard surface perhaps watch a little bit of Masterxeon1001 as he makes decisions with his own retopo on his sculpted bot.