
An example of how it used to be.
August, 2004, so 21 years ago.
The 'bar' at the top is a rolled up Windowblind, Treetog's "Antares".
The rest was done working directly from Treetog's skin - manually reworked to become a LiteSTEP theme [with animations] as well as a WinAMP 2.x skin.
The learning curve for this was pretty extreme and almost entirely per-pixel graphic manipulation.
I think I'd have a second learning curve if I ever wanted to do it again.
The entire works on my part were in PSP6 [Renato probably did the WB in PS].
Back in the day we had "Community Skins" where someone would post a set of graphics and people would volunteer to create various 'skinnables' using them so they became an integrated set.
These days most of those 'skinnables' are at best 'retired'. Microsoft has since made it hard enough just to do 'some' GUI modding at all, so getting a current functioning Windowblinds skin is achievement enough...