Randomly, I picked the stencil style and went for "Man with beard base jumping from the Eiffel tower." It produced one really poor image. It wasn't stenciled looking at all.
Next I went for pop art and used the prompt "Frog riding a motorcycle". The art style looked like something that an 8 year old would draw, not Andy Warhol (which I believe is the artist in your screenshot).
So I think you have some work to do in taking the inputs from the user and crafting them into better SD prompts that generate outputs that look like t-shirt artwork and in the styles they're supposed to be. I'd also drop the voice prompt support, no added value here. Definitely would prefer to type it on my computer and mobile keyboards already have a voice-input button.