Happy relationships generally have a ratio of at least 5:1 positive to negative interactions.
Of course its more complicated than this but the 5:1 ratio is a simple yardstick.
Studies (e.g. Dr John Gottman’s work) have shown that having at least 5 positive relationship interactions for every 1 negative interaction predicts having good relationship health at later time points.
You could quite easily count your positively-toned vs. negatively-toned interactions. You might notice some patterns that could help you e.g. missed opportunities for positive interactions, behaviours YOU repeat despite them consistently leading to negative interactions, or times of the day/week your ratio is best/worst.
The most useful time to keep this ratio in mind is probably when you’re stressed, depressed, or anxious, since being stressed out etc can easily lead to slipping into having more negative relationship interactions or becoming self involved and having fewer positive interactions.