One thing that I'm struggling with is having the right amount of icing. I realize that this will come with experience, but with lack of experience, I feel like it's wasting money.

I'm starting to get the hang of how much icing to make (like just in general -- knowing what the recipe makes, knowing how much is needed to ice the cake). The number of times I've not had enough, too much, etc. Sometimes it's only by a small amount that I don't have enough, and then I have to make more, and then basically have a ton left over. Also I struggle when it comes to having different colors of icing...

I feel like I can't gauge how much I need. Say if I need three colors: white, blue, green. I tend to put white between my layers, always.

When it comes to doing multiple colors -- I just can't figure out how much I need of each color. Like set x amount aside for white, set x amount aside to make the blue, and set x amount to make the green.

Like one cake I did -- white icing in between the layers. The rest of the cake was frosted in blue, which took up the rest of the icing I had. I had to make a new batch for some yellow piping, and I just ended up with a ton of yellow icing left over.

Especially when it comes to the colors, I worry about running out because I'm afraid I'm not going to be able to get the same shade and it's going to look all wrong.

And basically at the end, I tend to have a lot of icing left over, and I feel like it's a waste of money. I know that many icings can be stored in the fridge for so long. Sometimes I bake soon enough to where I can use it; other times I don't.

Does anyone have any sort of basic or general guideline to get them in the ballpark of the right amounts?

In general for each cake mix used one batch of b'cream icing (using 2#s of sugar) is needed.

...............Like one cake I did -- white icing in between the layers....cake...frosted in blue, which took up the rest of the icing...had to make a new batch for some yellow...ended up with a ton of yellow icing left over...........
In a case like this cut your recipe in 1/2. Use 1 # of sugar (of course, ALL ingredients are cut the same amount) or cut even further using 1/2 # sugar. Then color only 1/2 to 1 cup of that whatever color needed. Leftover b'cream can be frozen Save it for another day.
OR if you prefere you can add a bit of cornstarch (Or meringue powder) to stiffen it up a bit and make flowers. Swirl dropflowers, bacholer button, apple blossoms, even violets are always nice to have on hand for those last minute orders. Just pipe the flowers on wax paper, allow to dry *UNcovered* at room temp. overnight, then store in cardboard (NON airtight) containers. They keep well for 3 to 6 months in a dry place. YES, b'cream flowers will *air dry* nicely. Roses may take 24-36 hrs to dry but flat flowers usually are dry in about 8 hrs.

Thanks for the suggestion! I'll try to do that and see if I can at least save myself from making way too much. I don't think it's necessarily bad to have left over, but I just feel like I've wasted sooo much frosting.

I will try doing that.

And I didn't know that buttercream could be frozen! I knew it could be refrigerated, but didn't know about the freezing. How does it turn out when you thaw it? Also, how long can you keep it frozen?

LOL I have no idea how to do flowers yet. I'm hoping to learn that at some point in the near future, and then I can start using your suggestion with the flowers. I know I'll want to do them (a lot) once I learn.

I'm still having this issue too, though I'm improving with each batch. I put my leftover buttercream in ziploc freezer bags or tupperware containers (even the cheap ziploc or glad ones) and when I need it again, I bring it out and let it thaw a while, then put it in the mixer or use a hand mixer on it for a few minutes. Viola! Like I just made it!