Set aside devices at certain times, such as bedtime, during dinner, and when talking/during romance.
Write a note to each other each morning expressing love and appreciation.
Line up a babysitter, or set aside your work emails. Plan a weekly date night; not the same thing or the same old restaurant. Plan an experience, like rock climbing, yoga, zip-lining, concerts, exploring a new town. Or find activities you can do together on a regular basis.
Take the Gary Chapman’s “5 love languages” quiz online at https://www.5lovelanguages.com/profile. Share the results with your partner, and find ways to meet the needs of each other via those "languages."
Plan weekend getaways to connect and unwind. Explore nearby places: nature, museums, tourist attractions. Even a day long “staycation” in your own town can reset your relationship to dating mode.
Try, as hard as it may be, to use "I" statements when you're angry, and to apologize if your partner is hurt.
Use conflict resolutions strategies when disagreeing. Never resort to sarcasm or passive aggressive jokes at your partner’s expense, as contempt destroys your partner's sense of self.
Remember that the flip side of the things you love are the things that annoy you. For example, your partner’s spontaneity can manifest as them leaving unfinished tasks. Their housekeeping skill could make them critical of messes.
Make time for affection, intimacy and sexuality. Prioritize romance. Remember why you fell in love.
Don’t be afraid to ask for professional help rather than struggle. The longer problems are avoided the more entrenched and the more complicated they become. Power struggles, avoidance, distance and disconnection don’t help to solve problems, but to deepen the void between you.