this recipe from Annie's Eats that does require meringue powder so I'll let you know in another week if it's better or the same. I can tell you that as of right now I think this recipe is perfect the way it is and why buy a $4-$5 thing of meringue powder when egg whites do just fine. Actually better than fine...it tastes great and it is very workable!
2 large egg whites
2 tsp. lemon juice
3 cups powdered sugar
Place egg whites & lemon juice in mixer and mix until combined. Add the powdered sugar and mix on low to medium speed till combined and smooth. Transfer to airtight container or use immediately. When using cover your bowl with plastic wrap and place your decorating bags in a small glass of water with your tip pointing down to keep from drying out. Royal icing hardens when exposed to air.
*My instructions are great for experienced decorators or for those that are familiar with it but if you are new to it all I would suggest checking out Annie's "How to Decorate with Royal Icing" post. Hopefully one day I will have my own step by step picture instructions but until then please check out her site.
To decorate I used Wilton disposable bags with couplers and tip #3, I also used Wilton colors. To decorate the cookies outline the cookies first and then you will flood the cookies to "color" it in. Before you flood it I would add a small amount of water to your icing, mix in 1 tsp. at a time until it's your desired consistency. There is many methods to flood it, you can use a spoon to pour icing on the cookies and your finger to spread it, use a ketchup/mustard bottle you get at a dollar store/restaurant supply store, or squeeze bottles that you can buy in the cake decorating department. And then let dry and harden before you stack them or place them in bags.
Adapted from Joy of Baking.