Not much advanced technique here. Dollop some foam in three stacked circles and then etch away.
I was going for Santa, but ended up with more like an elf. I started with a tulip pour without the finishing pull-through, dragged some white up for the cap, and etched in the rest. The beard is just swirled all around. Done in a paper cup.
I don't know if anyone else has done one of these angels before, but for me it was an original idea. The wings are rosettas that I finished off down their sides and not the middles, then dumped out lumps of foam for the head and body. Minimal etching was done for a halo, mouth, and arms. Here's a free-pour version of the same thing: