What you will need:
An old oversized t-shirt (check your dads/boyfriends closet// fabric scissors// fabric chalk// measurement tape// fabric glue// black fabric// black string// a needle// an old magazine
First, your going to make your shirt into a muscle tee by cutting off the sleeves. You can make them as low as you want.
Now measure out where you want the cross to be. You can make it as big as you'd like, it doesn't really matter.
Using your measurements, cut out the two pieces of black fabric using your chalk to mark it. I used some left over fabric, so I cut out two strips.
Next, pin your pieces of fabric where you want them to go on your tee.
Now it's time to glue the cross on. I had to glue it in different sections, because of the instructions on my glue. So I would just suggest to follow the instructions on your fabric glue.
This is optional, but to make sure the cross stays on nice and secure, I sewed the outline of it with black thread. It's not very noticable, but I actually quite like the way it looks anyway.
And that's it!
Let me know what you think in the comments. :)