I love Steam-A-Seam....no brand loyalty, it's just what the craft store by me sells. I was about to get 5 sheets (with a coupon) for less than $3....and I'm able to create applique-like fun 'stuff.' I recently made this onsie for my Goddaughter's summer collection. I used some fabrics I had in my scraps. I cut out two pieces from the bonding material to the same size.
You gently pull one of the white pieces of paper off the steam a seam and there is another white sheet and a little sticky film. You put the sticky side down (it can be repositioned at this point). You then press the fabric side with an iron to hold it in place before pealing the second sheet of white off the back (the red piece just has the film left).
Stick the fabric wherever you want it, and then iron it down again....again....it can be repositioned.
This should stay in place, but if any of the edges are popping up after you wash it, you can just iron it down again. I ironed the red onto the green, and then both onto the onsie.
To jazz up the watermelon I sewed on a few button 'seeds' and a ribbon.