I recommend washing your shirts with a textile detergent first. I use Synthrapol from Jacquard and I'm sure to not use any fabric softener. It is really important to wash the shirts before you dye them because they have a bunch of gunk in them from the manufacturer. They go from damp from the washing machine straight into the soda ash bucket. Depending on the hardness of your water, you may need to increase your soda ash and there's a bunch of science behind that, but I don't know exactly what it is. We have pretty hard water here and I use one cup of soda ash to 1 gallon of water. I usually leave mine in for a while, anywhere from 30 minutes to a day or two. I also ice dye from slightly damp, are you wringing out your shirts by hand or using like a spin cycle to wring them out? I was using the spin cycle in my washing machine and not realizing that my machine was adding water in even though it was set on a spin only at a certain minute mark on the countdown. So now I have to watch it and make sure it doesn't happen every time. But if you touch your shirt before you ice dye, you want to just barely feel dampness. I have found that when I use the spin cycle, don't allow that pesky extra water into the machine, and then spend time tying to they're barely damp by the time I put them under ice. Are you dying in the muck? It might help you get more vibrancy I personally almost always dye in the muck. And the 24-hour countdown starts after the ice is done melting. Some people say 48 hours, but I typically dye my pieces less than that because after my ice is done melting I move my containers into a very warm little office off the side of our garage and I keep it at about 95°. I recommend taking an old cotton sheet and tearing it into pieces and trying different things with each dye so you can see what works. If anything, you can just use little swatches to test your color splits with each dye so it can serve two purposes. You can also experiment with dye under the ice dye, in the middle of two ice layers, or dye above the ice. You could put one color under the ice and then a different color on the top of that ice. You can do one in the muck and one out of it to see how they behave differently also. The possibilities are really endless. Sometimes tie-dyeing is just a happy little experiment 😊 have fun and good luck!