Is there something interesting (e.g. a fern or another, nearby flower) that you’d like to be in focus or that you want out of focus? If the former, use a small (f16) aperture. If the latter, use a large aperture (f2.8). [Some cameras have a preview button, which allows you to see, through the viewfinder, the amount of depth of field—before you click the shutter]. A slight shift in the position of the camera can help create a “stacking” effect of blurred blossoms in front of and/or behind the flower in sharp focus. And, such a slight shift can eliminate a distraction from the background. If there’s a lot of green foliage in the shot, it often shows best with about a -2/3 exposure adjustment. The best camera angle is usually to get low—close to the level of the flower. Shots from too far above, “looking down” at the flower, are seldom compelling. Shots made from the level of the blossom, or even on your belly or your back (looking up) can often be more dramatic. Or, try laying the camera on its “back,” with the lens pointing skyward, among some flowers and capture the “worm’s-eye view” of the underside of the flower against the sky (pre-focus and then use the camera’s self-timer for this and dial in a “minus” exposure adjustment to under expose since the bright sky may tend to “fool” the camera’s internal meter).