Hello Ross. After looking at your Flickr images for a while, I would recommend that you spend more time with your camera – specifically, looking through the viewfinder. Framing and focus are the foundation of every image, being vital in the process of representing a scene or subject to the viewer. Think very clearly about what you want in focus and where about in the frame/composition that subject needs to be in order to best present it to the viewer. If you have several focal points, you need to balance their positions in the composition so that the eye can easily move around them and none of them detract from the others.
Using your viewfinder to consider a scene assists you by placing a frame around it and demanding that you fit everything into it. This, and refraining from a zoom lens in order to make you manually zoom (walk around), will really help in improving your composition skills. After a while, you will start to ‘see’ a scene when you’re not looking through the viewfinder.
As others have said, you need to pay attention to vertical lines because most of your images are on the piss a little. Use the grid overlay on Lightroom to help train your eye. Your camera may also have a grid setting for the viewfinder.
Your developing is rather nice; quite sympathetic. Many new photographers go too far with digital developing just because they can. Perhaps play around with pulling the highlights back a bit in order to bring some more definition to the sky/clouds.
Using the manual setting on your camera will teach you quickly how to get the correct exposure. Being able to instantly review and image is the real boon of digital photography, allowing you to experiment with different settings.