I made my first decorated cookies yesterday. Just for practice thank the Lord. I am pretty pleased with how they came out but I had some ?'s for the experts
I used NFSC and Antonia's icing.
How long should I wait before writing or piping details onto the first layer so that it doesn't sink in? (this one is pretty ok, but the first one was not dry at all. DH ate that one so there is no evidence)
on the close up with the arrow, it looks almost like the butter in the cookie is soaking through this icing can u see how it look darker?
Am I correct in assuming that u pipe details with stiff icing?
I know I have read some of these answers before and I thought I watched the threads for reference but I can't find them now..
Oh yea, I went to a demo with Fairytale yesterday and I got to have one of her gorgeous cookies! she is really great and she got me wanting to make fondant covered cookies now.
I think your cookies look fabulous...
generally I wait a day after doing the base icing before piping the details, and i do them in stiffer icing...
i'm not too sure about the butter from the cookie soaking through the royal icing... that's never happened to me before! was your icing mixed really well? the only thing i can think of is that perhaps the liquid wasn't fully combined... did it happen on only one cookie?
sorry i can't be of more assistance, maybe someone else out there has some ideas too 
it happened on more than one cookie. I had some that were iced but with no detail. yet. I mixed the icing for about 10 minutes on low like the article said. I have made royal before but I think I mixed it fast. I know this is like modified royal.
Your cookies look great...can't believe it was your first time! I am just beginning as well and am curious about your question as to use the stiff or thin icing for the details. I thought it said in the tutorial to use the thinned icing but when I did that the details all kinda ran out rather than stay very defined....maybe my thinned icing was too thin? I don't know! I'll be watching this thread for more responses. 
Your cookies look great.
I can't see that the icing looks darker.
When I don't want the icing to sink in , I just wait about an hour or so. If you are using a small tip like a #1, you should use a thinner icing.
Keep practicing and all the kinks will get worked out.
Quote by @%username% on %date%
%body%