The easiest way to get sharper photos is to use a tripod. That will eliminate camera shake. And, don’t forget that if you’re using a camera that has a vibration reduction feature or a lens with this feature, turn it off when you’re using the camera on any steadying device. If the camera is on a tripod the anti-shake devices will keep looking to see why there isn’t any shaking for them to minimize and thus this behaviour creates more shaking.
But it’s no fun carrying a tripod around with you all day, especially when you’re on vacation, so what I do is carry a mini tripod. I’ve been meaning to buy one of the big “gorilla-type” three-legged devices which can stand like a regular tripod or be wrapped around a tree branch. Best of all, these supports will fit into a medium-size camera bag.
Another trick is to bring a tripod or, better yet, a mono pod (it’s a a one-legged tripod that helps steady the camera) only to a location where you’re certain you’ll need it. For example, if I’m going night shooting I bring some sort of support so I can take time exposures.