So, first things first! You’re going to need to be used to drawing your character, so that you have references! Or have some form of reference.
The first thing you’re going to want to draw is the character in their correct proportions. Which are typically measured in reference to the head. In Blue’s case, he is 4 heads tall! Which is half of what humans normally are, being 8 heads tall.

With this first drawing, you can mirror it, and then draw the backside over it, using it to help maintain proportions!

Now for the more tricky part, the side view!
You’re going to want to lay your front and back views side by side, using them as reference to the height of each part is! I even used a transparent underlay of the front facing drawing to get the locations right.


And for the other side I just mirrored it, as Blue is a symmetrical character, however you can just follow this process the other way around to do the other side!
I didn’t have enough commitment to make diagonal frames, but you can use the same process for those as well!

There will obviously be mistakes, which you can fix during the merging process!
For example, the front and back frames’ arms were too high up in comparison to the side views, and I forgot to add the rolled up pant legs!

I hope this helps!