I've just done white icing! Nothing exciting, I'm afraid.
To be honest with you....I never crumb coat. I just put my frosting on. I've never had problems with crumbs and it saves me one extra step by skipping it.
I always crumb coat. I use thinned down crusting BC. I find this not only keeps crumbs out but also helps seal in moisture...the cake won't dry out if I have to hold it for any length of time. I usually crumb coat all the layers of the cake in question and then refrigerate.
I also find crumbcoating is really helpful if I have to do the upside down icing technique.
I heard someone would take APRICOT jam .... must be apricot for some reason, not guava, or mandarine, etc.
Put the jam in the microwave until it boils. Wait until it cool a good deal, but still warm. Ice the cake. The molecular structure of the jam changes to become similar to fruit roll ups and such. Crumb coats the cake and adds a bit of flavor dimension. Not much, but pleasantly noticeable with some cakes.
Haven't tried it, but will later.
I read in a vintage cookbook that I was considering purchasing that apricot jam was not only used to crumb coat a cake, but also to adhere rolled fondant to cakes, instead of buttercream. I have never done this, as I doubt very much that a cake without buttercream icing would never be acceptible where I live. The book also mentioned orange marmalade being used in the same fashion.
Theresa 
Quote by @%username% on %date%
%body%