The easiest way to improve your camera's image quality is to put a better lens in front of it. There are over 70 lenses in the current Canon lens lineup and each fills a specific niche. Unless you spend a significant amount of time reading the reviews, you need some direction in finding the right lens or lenses for your specific needs.
Owning or having owned all of Canon's current lenses along with a significant number of third party offerings from manufacturers including Sigma, Tamron, Samyang, Tokina and Zeiss, I find myself uniquely positioned to guide your lens selection. Lenses for various budgets are included in my recommendations.