You may want to contact a couple local muralists to see what their recommendations are. I love the look.

me too!!!!!!!! :*

I'd go with Emily's suggestion, I've seen "home-made" clouds done before and they've not been pretty.

Im not using the google to find but there are wall paper type products you can buy and just paste it up.

Some things to consider. There is perspective of the clouds and aerial perspective of the atmosphere. Do you want the sky to seen like its morning, afternoon or evening? This will determine the overall color and feel. For these items you should hire a muralist and make sure that they use an air brush for this job it will give the look a softer feel. You will need to see their portfolio. Make sure that they know of these things that I mentioned. Hope it turns out great!

Hi All! I painted the clouds on the ceiling, and used a bluish grey, instead of white since the ceiling was already a deep greyish blue. It worked great for a teen boy. Not too childish at all. You can find a video of how I paint clouds here:
You can also find more of my work at my online portfolio here: www.muralsbymorgan.com

See Muralist Morgan Bricca's tutorial on You Tube:)!