I usually go for this kind of shit. Some color contrast in the attire, not very high saturation pastel colors. I don't like jeans because they're very noisy to look at. T-shirts are completely fine though as long as they're not too large.
As for shoes, I usually just take some sneakers. I don't think they matter very much in the posture of someone as long as they fit your overall style.
photo has kind of bad lighting sorry