A few times ago I was given a t-shirt because there was a small tear on it... I thought that's not a problem because I'm used to mend my husband's wool sweaters. But the mend was to be done on a stripe... and it was difficult to make it invisible
Once the mended done, the result wasn't as good as I waited. So here come's my tutorial in the joined file.
Today as I traduced this tutorial, I found a fun and simple idea of personalization with a bleach pen.
Hoping that both tutorials gave you some ideas...