I am a card/paper modeler and I used to build a lot of scale models but kinda got distracted with 1:1 scale props for a while. I always wanted to scratch build a Y-wing because of all the little greebles and details and decided my skills had progressed where I should be able to do a decent job of it. I found a 2D blueprint online that I thought would help with the basic shape and scale but I have had to fine tune and correct it alot so far. I am all but finished with the "head" of the ship and the only thing I am unhappy with is I ended up putting the torpedo launchers a little too far forward .
You can see in the pics below I am starting with the basic shape and then layering on detail from there. The cockpit was pretty tough since alot of the detail was between 1-3mm at most.