Selective focus isolates the subject of your photo or isolates the portion of the photo to which you want to draw the viewer's eye. While isloating the subject, the rest of the photo will be out of focus, even blurry. If you are using a DSLR, use the widest f stop of your lens. If you're using your phone, try using portrait mode. If you need more information on selective focus search on google and you'll find all sorts of articles on it.
It's our first scavenger hunt of the year. Use selective focus in 4 ways; looking up, looking down, looking through and get in close.