Take the old picture frame, and gently sand it with a sanding paper to get rid of any dust or edges. In addition, it will also smoothen up the frame completely that will aid in painting the frame and sticking the collage pieces to the frame.
Now take a craft brush or a small paintbrush, and start painting the frame to give it a new look. It is recommended that one paints at least two coats over the frame.
After your paint has dried up, think about a collage theme for you picture frame. For instance, if you are making the collage frame to gift someone, then think about something that is loved by that person. If you are making it for yourself, then think about something that you really appreciate.
Once you have come up with a theme, it is time to collect the items needed for making that collage frame. Glue those items to your frame. Make sure that the items stick to the frame properly, and will not fall apart. Once you have applied all the items to make the collage frame, allow the frame to completely dry.
After your collage frame has dried up, take the craft sealant, and apply at least two layers of it with the help of a small paintbrush. Allow the sealant to dry before wrapping it in the paper or hanging it on the wall.