This year for Christmas gifts I'm doing tie dye tshirts and I've started already so I can do some shirts for us as well!
Since I prefer just one colour for my tie dye I don't do it the correct way, I use normal clothes dye where you soak the fabric in a bucket. I always have spare onesies on hand as there is always room in the bucket for some tiny baby clothes - plus they make great gifts for baby showers.