Help?

Hey guys, i wanna go about making this a t-shirt, this is a serious decision im thinking about. 
But the thing is, I dont know how to go about it! 
I dont know what to make negative space, i just know its going to be neon/pastel colors on a black shirt...
Please help??? 
Im very attached to this idea and atleast want to say I tried. yknow? 

design (c) me