Hi Henrik -
Yes, you are right, I rarely do freebies anymore, and then, only in needy, non-frivolous personal situations. For example, I've recently did some free work for someone who privately contacted me who was preparing pix for a funeral of a loved one. OTOH, I completely ignore requests to remove Snapchat bars, add muscles to teenage boys, place models and actresses next to teenage boys, etc. LOL.
In contrast, I'm delighted to teach, give pointers, etc.
For your photo, all I did was slightly darken the underware, particularly, the elastic band, using the gamma slider on a masked "levels" adjustment layer.
Then I went over each letter with the pen tool, stroked the resulting path with white (on a separate layer), set the mode of that layer to "screen", played with the opacity, and I was done.
Although you didn't ask for it, I felt that the image you posted was a bit soft and lacked punch, so I added a tiny bit of large radius USM to the bag and its contents.
HTH,
Tom