Supplies are simple some felt, scissors, needle, DMC floss, buttons and velcro (not pictured here.)
I cut out pieces of felt in the size/shape of a flat envelope using pink shears. I like the zigzag detail that pinking shears add. Also I cut out a couple of hearts to hand stitch on (do this first before you stitch up the sides, it will be much easier this way.) They I sewed on the button, which is purely for decorative purposes.
Make sure you stitch your heart on to the front (not where it is placed in the top photograph.)
I pulled apart the DMC floss so that I had 2 lengths of 3 strands. 3 individual strands of DMC floss will give you the appropriate amount of thickness to show up, but not too much that you are making it hard to sew.
Just do a simple stitch around the heart, and the up the sides and through the button holes. It's as simple as that.
No sewing machine needed.
Then on the back adhere sticky-back velcro circles behind the button, this will hide the thread from that and will give you an easy way to make the envelope stay shut with having to make an actual button hole.
Fill with fun stuff and re-use it over & over.
Of course, I made them in 2 different colors so the kids knew which belong to who.