So I cut the sleeves and a small section between the leg holes and the tree off the onesie and added them to the polo for sleeves and length (the polo was a bit short for H).
I also have a pile of adult t-shirts in various colors that I grabbed a white and a red one from and cut a small section for the tattoo decal. Using the template from the girls clip, I cut out two hearts and one of each banner piece.
the arrow on the white piece shows that direction the little lines you can see in your shirt are running (the grain). This is important for jersey as it's so stretchy, I didn't want my pieces to stretch up so I have the grain running vertically. Doesn't matter for the heart, mine was at an angle.
I hate pinning, which is why I end up sewing a lot of crooked projects LOL. To avoid pinning and crookedness I grabbed my fabric tac glue and put a dot where I wanted my decal, lay one heart on the dot, put another dot on, put the second heart right on top of the first. I used two layers for depth. Take it to your sewing machine and tack it down around the edges (I used black thread as tattoos are outlined in black).
Put your sewing machine away, we're done with it. Tack your banner pieces down with fabric tac.
Put a small glob of your fabric paint on a scarp piece, using a small paintbrush practice your letters on your scarp jersey to get a feel of how it applies. I used black tulip puffy paint, if you apply it with a brush it isn't puffy and holds up in the wash beautifully.
Now pray you don't mess it up and go for it.
I did simple letters first then went back in to add the tattoo shadow font effect they always use. (If you do mess up a letter don't fret, just paint the banner black and maybe leave a white edge, it'll still be cute!) Let dry, insert boy.