i think what i do is start with a melody and think about where i want consonants to be and which vowel to do as im making the melody, then i execute it and change it if it sounds weird or if it could be better. one thing i do is try to say it out loud and see it it's difficult to say, and if it is, then speak out how i want it sound, break it apart and recreate it (also when doing this a lot i learned a lot of like the speaking syntax if that makes sense)
If you ever have the chance! A lot of my "8-bit" work is heavily inspires by Snails house. Is not fully 8-bit but the melodies are incredibly similar, check him out to see it !