Although it may seem obvious, but spending time together is important. At first it's easy as honeymooners but as bills come and random busyness (such as kids) explodes, time together as couples gets pushed back. How you spend time together is important too.
As usual, this goes back to the love languages. Incorporate both of yours into time together. It doesn't necessarily have to be super special quality time. Even being in the same room is special. Still make sure to have quality time as being on your phone all the time can put a damper on things eventually.
My husband and I are a cuddly bunch, so we usually are next to each other even when on our phones. Focusing on one another all the time can get a bit boring and you run out of things to do or talk about. That's where phones come in haha. Be with each other, but feel free to have your own game to play. Couples have different interests and that's ok. I play this dress up game on my phone and he plays this power rangers game. We still spend time together even on our phones (like right now as I'm writing this).
Time is valuable and spending it with your spouse is an investment and a blessing. Too often we think that we need to make a ton of money and do something amazing. We tend to lose sight of each other and realize after a decade or two of marriage that we really needed to invest in our relationship more than our someday material future. Note: still be wise and plan for a good future, just don't sacrifice your marriage for it.