Some people have had good success using the Dominic system, but if it’s not really clicking for you, its ok to try some other techniques.
Have you looked into the Major System? It offers much more flexibility in constructing entries than Dominic, you can base your entire list on it if you want, and it provides a foundation for expansion if you ever want to try a larger system for numbers or playing cards.
With Major, you’re not limited to initials that may force you towards a person you have no connection with. This is a big weakness I’ve found with the Dominic system and one of the reasons I don’t usually recommend it. With Major you can use it to make simple first names and pick whoever you want with that name.