My kids had a few friends over and we made galaxy shirts.
start with a cotton shirt
lay out random circle objects-we used taped, lids and a frizbee
using a spray bottle spray a 50/50 mix of water and bleach
let it "develop" rinse
we then tossed the shirts into the drier on low
once dry we put in details like rings and dots of stars using a bleach gel pen
after the next round of bleach is rinsed off we washed and dried the shirts
once dry add the paint
I found a great bottle of spray white fabric paint, that really helps.
Once the paint dries remember to heat set.
These are great fun, and the kids had a terrific time. I really enjoyed watching their little customizations. One painted in a mini Tardis- instant Doctor Who shirt; another kid made sure there were 9 planets, added a rainbow bridge and labeled a few of the planets Asguard and Midguard--instant Thor shirt; one created cookie monster in space, and the last kid added arranged the planets for a solar system. None of these additions were guided or suggested. Its great to see how the took the concept of space and made them their own!
I plan on cutting them up to make mine into a deconstructed tank top.