I'm new to the world of cake decorating. So I've been using Google and Pinterest for buttercream recipes. I follow the directions but it always turns out thin and runny.  The last recipe called for 1c butter and 3-4c confectionery sugar. Still super runny and that was without any milk. I probably ended up using a couple of pounds of sugar before it was thick enough to decorate. Why is this happening??

The  recipe is bad...use 1 pound confectioner's sugar,  1/2 cup crisco, 1/2 cup butter, 2 Tbsp milk. Beat the fats together, add the milk and beat it in then add the sugar. Add more milk of you want it to be thinner.

Don't melt the butter before making it if that's what you're doing!

I was also wondering if the butter was melted, because just creaming butter and adding sugar shouldn't make anything runny, no matter what the proportions.

I have never melted the butter. I think I'm going to double check the quality of my ingredients, to make sure I'm using real butter. 

I sure hope I can figure out what Im doing wrong

raven, did you mean that you used three to four cups of confectioner's sugar or three quarters of a cup? the first would be ok the second is not --

i use one cup fat to two pounds (just over 7 cups) confectioners sugar and a half cup cream/buttermilk/liquid and flavoring --

but there are a zillion different recipes -- i used to not even measure anything and it always comes out -- the one i landed on is colette peters --

i can't imagine why yours is runny but like you said some of the spreads and maybe even the margarines can throw it off --

would love to hear how it's going when you try again

I finally realized I was not using real butter! I tried it tonight with real butter and it turned out great. Trial and error lol now I'm having fun trying out different extracts etc.

Glad you figured it out. I always use real butter and no Crisco. Try using flavor oils as well. You only need literally a drop! Make chocolate by adding cocoa powder or melted chocolate. 

Have fun!

this might help:

http://www.sugaredproductions.com/blog/video-making-american-buttercream/