Single-word verb for "to do from scratch"
Solution 1:
Certainly "templates" indicates you're at least peripheral to a computing topic, which makes me certain that the word bootstrap is perfect here.
In my understanding, there's the original Horatio Alger meaning, in which a self-made man had "pulled himself by his own bootstraps." Which is to say, given no particular, uh, template to start from, some highly successful types had risen to great heights.
In the computing world, that somehow became bootstrapping a kernel, in which hardware, absent any other instruction except "you're on" loads software into memory, causing the system to become a more fully realized computer.
But with computing's adoption of the term, of course the modern entrepreneurial world has seized upon the term to mean:
bootstrap - to help onself without the aid of others (dictionary.com)
Solution 2:
There weren't any available templates for my project so I had to create/build one/some
From scratch remains the proper expression if you had to create the project without templates. None of my younger native and non-native English speaking IT colleagues would have a clue what bootstrap meant; all of them would understand
There weren't any available templates for my project so I had to create it from scratch.