My daughter is in between pant sizes at the moment so I made her two pairs of new pants in the past couple of days. She has a favorite stuffed doggie and asked that one pair have dog appliques. The other she left up to me. I decided to go with free form flowers because I found the calico fat quarter that matched the pants material so well. I just sketched a flower shape similar to the one on the calico for the applique. I placed the flowers on different spots on each pant leg instead of on the knees. I learned my lesson about that last year when I made a pair of pink pants with heart appliques on the knees. They were in the correct spot for all of a couple of weeks before she had a growth spurt and they were between her knees and ankles and looked silly!
When I applique, I use a layer of Wonder Under Fusible Web to attach the appliques to the garment with a narrow, tight, zig zag to finish the edges. For the flower applique, I cut out the center shape and pinned it to the flower applique and stitched around it with the same zig zag stitch to make the inner ring seen in the close up of the flower.
I have attached the sketches that I used for the appliques as a pdf file below. Anyone is free to use them for noncommercial purposes. If you make anything using the appliques, please post a link in my comments section because I’d love to see them!