Well, here you can buy apricot glaze already made up from a local bakery, it used to be easy to come by but not anymore. So if you cannot get it, you get Pure Apricot Jam. Incidentally, most commercial bakers use this for crumbcoating all of their cakes.
Well the trick is, if you don't want the taste of the apricots, either you get the glaze already made and you measure it out and add 1/2 that measured out amount in water. In other words, 2 cups glaze, one cup water. Bring to a boil for about 5 minutes and it is ready to use. I keep it in a container in the fridge, it lasts for months, then I re-heat about 1/4 cup at a time in the microwave until it comes to a boil.
Can't get the prepared stuff? Well get some Pure Apricot Jam. Bring this to a boil for 3 minutes or so. Remove from heat and force it through a fine sieve to get rid of the pulp but to get all the juice. Measure it out and again pour half the measured amount in water, so 2 cups heated strained jam, 1 cup water and return to a boil and boil for 3-5 minutes. Again use while hot and refridgerate the rest until you need it.
Now generally the bought prepared glaze is a lot more gelled or thicker than when you do the jam one, but it works fine.
I level my cakes as soon as they come out of the pans, so I am brushing the hot glaze on a hot levelled cake. Generally most people level their cakes when they are cool, but still, heat up that glaze before you apply it. It takes about 25 minutes to set on a cooled cake, on a hot cake you will wait until the whole cake is completely cooled before icing it with your buttercream.
You are using a pastry brush to sparingly brush on this glaze, you are not soaking the cake with it, just enough to see that it was brushed on. So that means that about 1/4 cup will do a 14 inch round layer or so, so I do mean sparingly. The joy is that it takes only seconds to do this and you don't have to worry about smoothing your buttercream crumbcoat because the glaze doesn't need smoothing and you go on to actually icing the cake as soon as it is cool and set or you can cover it with plastic wrap at this point and wait until when you are ready or freeze it this way.
Commercial bakers do not add water to it as they also use it to flavour a cake slightly. Either way, it works great!
Why do I use it, well generally because I have a whole bunch of cakes waiting for a crumbcoat and this means I can crumbcoat them immediately and not have to worry about them drying out or setting an alarm clock to get up and cover them or crumbcoat them. Plus it works really well to seal in the moisture and the crumbs and it also means I don't have to put on nearly as much buttercream icing.
However if you are doing a cake with say, basketweave sides, well you will still need to apply a thin coat of buttercream before doing the basketweave so that the cake does not show through. But for anything else, well you just do your final icing over it, once it is set. I generally do character cakes with the stars directly over the glazed cake, I do not put buttercream first and then the stars.
Hugs Squirrelly Cakes