Step 1: Step 1
Step 2: Step 2
Start to build up a solid rectangular prism (cuboid, etc. a 3d rectangle) and shape the top into a slight arch of a dog's back.
Draw a line where you want to belly to end, and carve in the legs. Repeat for the other side too.
Grab a fist of snow, and press it onto where the dog's tail will be. Reinforce this mound with some more snow around where it meets the dog's body. Slowly and firmly press more snow onto the tail to make it as long as you want.
Step 3: Step 3
Just like with the tail, press snow on the front of the head to make a snout, and do make triangles out of snow for ears then press and reinforce them onto the head.
Lastly, get two shiny pebbles and press them into the head.
Congratulations, you're done! Take a picture :)