Patches should be created with `git format-patch`, so in every case you should be familiar with the basics of git. Make sure you develop against the master branch, i.e. **not** against any FluidSynth release.
Find FluidSynth's style guide below. Syntax related issues, like missing braces, will be automatically taken care of when compiling fluidsynth by calling `make` (provided that cmake has found `clang-tidy >= 5.0` on your system). An explicit reformatting can be achieved using `make format` (provided that cmake has found `clang-format` on your system).