I just thought I'd mention a little factoid about the challenges that I think is often overlooked and could be very helpful when working on ones that are truly, ummmm, Challenging. 
Whenever Doug posts a new challenge, he also posts a sort of "main thread" about it. Here is what the breadcrumb trail looks like to one that was actually pretty well utilized:
RetouchPRO Forums > Technique > Challenges > Restoration Challenges > Restoration Challenge #34
The very top thread, (HERE), holds an interesting discussion between people who were struggling with this particular one.
If you go to the Forums main menu and click on Challenges, you'll find that each one has such a main thread. I think that possibly posting notes about your questions and dilemmas in that area for challenges you have problems with might be of some help to some of you who feel that you are struggling with them at times...

Whenever Doug posts a new challenge, he also posts a sort of "main thread" about it. Here is what the breadcrumb trail looks like to one that was actually pretty well utilized:
RetouchPRO Forums > Technique > Challenges > Restoration Challenges > Restoration Challenge #34
The very top thread, (HERE), holds an interesting discussion between people who were struggling with this particular one.
If you go to the Forums main menu and click on Challenges, you'll find that each one has such a main thread. I think that possibly posting notes about your questions and dilemmas in that area for challenges you have problems with might be of some help to some of you who feel that you are struggling with them at times...