Just curious how others handle the situation when a customer asks for a design or detail that is either out of your comfort zone or done in materials/methods you don't use.

For instance, I had a bride who wanted a bottom tier covered in hundreds of fondant circles cut, rolled and glued to the side.  Being that I don't work with fondant covered cakes and instead ice all my cakes in buttercream, I explained that the weight of all those fondant piece can pull the buttercream off the sides of the cake and it's not a technique I am will to do.

I know a lot of bakers must make every sale they can, but I don't...I'd rather lose a cake than attempt something I am not comfortable with.

How do all of you approach these situations?

I am in a similar situation and I am like you, only use buttercream. The worse part is, it's my brother. I basically told him this is what I can do and offer you and anything outside of that is not my expertise which will not be guaranteed. 

I too only use buttercream or stabilized whipped frosting but I am just a hobby baker. Sometimes I make my neighbors cakes just for the fun of it but always using buttercream or whip cream flowers for piping. I can not stand the taste of fondant. Growing up I remember  when going to weddings the wedding cakes I only saw were buttercream cakes. I think fondant cakes have gotten popular with some people but as for me I will stick with the ole fashioned kind with buttercream or whipped icing.

I generally say no if I've already got orders for that date, or if I get a 'troublesome customer' vibe from the client, or if they've already made it onto my 'no cake for you' list, or I'm trying to keep a particular date free.

Unless it's a technique I'm really not familiar with like Lambeth or intricate string work, then I am happy to do a practice run and learn something new.

i can only remember saying no re: expectation versus price -- otherwise for the most part it was game on --

I know that my reply won't hold much weight here (as I do this as a hobby, not as a business)... I have so far only said no once, to my friend for her wedding regarding perishable fillings (long story, it's posted here on the forum). As for decorating, as much fun as it is for me to be in my "comfort zone", I don't turn away a challenge. Especially when there's time for me to research, learn and try out the new technique. But I acknowledge that may not be realistic if money and my reputation were on the line.

Your cakes are AMAZING, by the way!!! Stunning! I hope to be as good one day.

And then there's me, want to try everything at least once. it fun and I figure out what I like and don't