One of the more insightful, if annoying, aspects of posting photos here is that one begins to notice all the things that look wrong about one's fit - usually well after it is possible to change it. Thus it is today with the fit of my jacket, which seems to be pulling slightly in the chest (at least to me), as opposed to today's trousers, which are more than a bit loose at the waistline. Argh.
This is all meant constructively, no offence meant:
Understand your face and body type. You are skinny, have a long neck and a high forehead. The skinny means that you will drown in many normal-sized garments. You will look like there's a suit carrying someone around, rather than vice versa. It also means you have to be careful about accessorizing: big cufflinks, shiny ties with big knots and the like will only exacerbate that.
The long neck means it's a bad idea to have the long collar points you have. You will improve balance no end by getting wider-spead collars. It also means you might need a higher collar. It might be useful trying out MTM shirtmakers.
The high forehead calls into question your hairstyle and facial hair. Your current hairstyle accentuates the forehead, and your facial hair makes the lower half of your face very busy. Combined with the long neck and skinniness, it results in an unflattering picture.