Thanks for the feedback!
Japp, I saw the "View Custom Product" link but when I was redirected to the cart page after I've created my (awesome) new T-Shirt I was like: "Where is my shirt gone" :-O.
That said, it would be great if a picture of my (super awesome) T-Shirt was displayed in the cart overview immediately (instead of the default one) without me having to click that "View Custom Product" button.
that would improve the flow a lot ;)!