if you don't want to do needle turn for the snowmen - i would make them with either non fusible or fusible interfacing (one sided not 2 like the fusible web your using).
if you want to use the fusible type you would trace the shapes onto your fabric and onto the fusible interfacing. sew them together (right sides together) then cut a snip in the interfacing and turn the piece out (like you would a pillow).
fuse it in place and then use a small blind hem stitch with matching silk thread to attach it permanently down on the background fabric.
be mindful here that the interfacing isn't peaking out from the piece, although with the white snowmen its not so critical since the interfacing is white too.
if you want to use the non-fusible interfacing you would do the exact same thing as above expect i use water soluble thread.
once you have the piece pressed the way you like it, give it a shot of steam or spray with a little water to dissolve the thread.
the interfacing will remove from the piece and you are left with only the needle turned fabric piece.
and then blind hem stitch in place with matching silk thread.
the up side to this, since you are making numerous snowmen you can reuse the interface pieces over and over again.
those tiny little arms are stuff are going to be harder because they aren't even wide enough to have a 1/4 seam on each side.
so you might want to fuse them on with webbing and raw edge or do the needle turn thing like above except trim those seams to 1/8 inch.