For an hour walk where a photo opportunity could happen at any time, I carry camera and lens in my hand with a wrist strap for security or if I have to use my right hand for something besides holding the camera. The Lowepro sling bags are very convenient; the camera is quickly accessible. the bag has a. cross shoulder strap and a waist strap keeps the bag from moving around.The design has changed some from the model I used for several years. Even if you carry the camera in your hand, the bag is there if you need some accessory, rain protection, etc.
I quit using neck and shoulder straps because they would swing around a lot and were sometimes in the way. I tried a vest system but it was too hot in warm-hot weather. The chest strap, favored by many binocular users, was also too ristrictive for me. Since I often am taking photos close to the ground, if the camera is attached to my body, the strap usually has to be removed and often gets in the way.