Welcome Edward, to our new forum.
The best way for creating an ODF depends on your requirements and your skills.
The most flexible way is simply to write the code with an editor. Here you can implement all options of GrandOrgue ODF, like graphic screens, multiple panels, key and stop noises. But this way needs more skill in programming and some tools to generate very large stop descriptions with multiple releases.
More fast and easy way is to use a generator program like Organ Builder. But with this it is not possible to implement all features - only the basics without graphic screens. (The original link to Organ Builder doesn´t work any more, but I now have added it to our downlaod area
Personally I use a solution where PHP programming is included into ODF code. This is the most flexible and maintainable solution in my eyes.
You can find a further summary of solutions here:https://github.com/e9925248/grandorgue-odf