When I know that I should use a tripod, I often use "the Pod" (available from B&H and others. It is a very small bean bag which comes in two sizes and one variation with an offset camera mounting screw as opposed to a centered mounting screw. It is very light and small (I use the larger size.) Cost about $15.00. I find I can put it places, such as on rails and posts where I couldn't use a tripod. Sometimes I just leave it on the base of the camera so that it is instantly available. Look into something like this.