I’d like to contribute my thoughts and suggestions about this topic.
I never used the Fontself template, because I had my own solution before Fontself published their template.
So I can’t compare, but I’d like to give some hints.
Often characters consist of two or more overlapping outlines in the creation phase (see screenshot below).
But Fontself maker can’t handle this, so the paths has to be merged.
So if you want to make changes to the character later, it’s much more difficult than with the separate outlines you had before.
For this reason I have two Layers “Work” and “Final”. I draw the characters in the “Work” layer and copy them to the “ Final” layer, when I think I’m ready. There they can be merged without loosing the original paths.
Different fonts may have different x-heights. Cap-height and descender may vary too. So the guidelines has to be adjusted.
To simplify selecting them I have four sub-layers for the different types of guides.
So to select all the appearances of one type of guides is just one klick away (on the very right side of the layers name).
The “Temp” layer is for temporarily needed support of any kind (and it’s used regularly by me).
If you want to take a closer look at my template:
Voilà, here it is:
This PDF can be opened by Illustrator.
The displayed character set contains the whole “Adobe Latin 3 (CE)” set plus a few from Adobe Latin 4.
For commercial use you should add all this signs to your font.
If you want your font just to be for private use, you may skip a lot of them.
@Franz: Please feel free to take up whatever you want to use in following versions of your template.
All the best and happy fonting