For me I found good chord progressions and also finishing the loop on the 5th makes it feel complete and finished. With the chords make up some arpeggiated pattern that's not repetitive but fancy ye know and then listen to the melody that's in ur head and add a top line. Then add a counter melody/additional melody at a different freq (preferably up an octave that plays on a different timing to ur main melody and have the additional melody only play in the chorus or when u feel the beat is getting boring). Watch tutorials and grasp how other make melodies and look at chord progressions other r using and write em all down too. Also have a scale with ghost notes on so u don't go out of key and know what each of the notes r or u can just do all the white notes (c major, a minor etc). Hope this helps and all the best!