How to learn design principles, and adapt them into my work?

I'm a Junior Web Designer, I've been in my role for 3 years, however, I've constantly struggled in this job, with very little support from management. I've been told that my layout and composition skills are lacking, and that I struggle to generate ideas from a blank piece of paper, I've also been advised that the best way to improve this would be to re-learn/revise design principles, i.e. unity, balance, contrast, space, hierarchy. I'm currently looking for a new job at a relatively junior level so I can actually be taught these skills rather than just left to my own devices. I feel like I've gone over these principles multiple times, but I'm unsure how to adapt them into my design. I'd describe myself as a designer who is 'rough around the edges', I believe with the correct guidance and direction, I will be able to succeed at the moment, but I don't feel at the moment I am getting this.

Because I've come from a Computing background, rather than an art or design background, I haven't really had these principles hardwired into my brain naturally, it kinda feels like I'm now playing catch up, and I've never really been taught them by my employers. I've leave my portfolio, where you can see some of the work I've done, if it helps you assess what my problem areas are, and where I need to improve, just to be clearly, **I'm not looking for feedback based on your personal design preferences**, I'm looking for feedback on where I'm lacking in rules of design and the best ways to adapt these to my work going forward: [www.shaughnwilliams.co.uk](http://www.shaughnwilliams.co.uk)