Axion lense flare 2 is a freebie on the axion site. It has a bug in that when you get the flare just where you want it in the small window, it shows up differently in the image. The fix is to immediately undo, go back to axion, and reposition it. The second shot will be exactly where you want it. You might use a masking tool to select a portion of the layer where you want the flare to show. Another trick would be to mask the area and just use a blur or gausian filter. Axion or the tricks that others suggested above would be better.