My white royal icing I thinned for cookies looked like marshmellow fluff. It set up fine, but had many air like holes. Not at first, they looked fine until they dried. They also didn't have that shiney look to them. Did I make it to thin?

Royal icing doesn't dry with a shine, it usually dries with a matte finish. Also you can pop airbubbles right after you flow the icing, using a corsage pin or toothpick.

To get rid of the air bubbles when you finish mixing the icing give the bowl a couple of sharp bangs. This will bring most of the air bubblues to the top where they will burst. Cover and allow to stand for 1/2 hour the rest should also rise and burst. When you come to use the icing just mix it gently to ensure you don't incorporate any more air bubbles. To get a gloss finish dry under a reading lamp for 10 -15 minutes and this will keep the glossy look

Thanks for the tips.

MissBaritone - what a great tip...will any lamp work?

I think the tutorial that Antonia has posted has a section about air bubbles in the icing.

Yes, you can get rid of at least 80% of them by giving the thinned icing a good hour to rest. (I leave mine overnight sometimes!)

They rise to the top and you can get rid of most of them with just a few strokes of a spoon or spatula.

Thanks so much!! I had thought maybe I put too much water in as I thinned it to put into bottles. I will try the lamp since this is something I already have.