Don't be afraid to jump into sks6 headlong and just "figure it out."
Also, find other well designed skins (try to stick to master skinners if you can--vStyler, Tiggz, NightTrain, to name a few) and study them. See how they were done, and why certain settings were used. Make copies of skins and change things to see what happens.
Once you begin your blind, be prepared to spend several months hashing it all out.
Oh, and don't ever become content with the quality of your own work! 
