1. Jealousy. Just how envy is one of the 7 Deadly Sins, jealousy is also bad for your relationship. Now, from time to time you may get jealous of your partner, that's natural. Maybe they got a promotion after you've been working toward one for a year. Maybe they have free time and you're always swamped. Maybe they get hit on when you're out on the town. Whatever the case may be, it is important to put that feeling on "the shelf." Working towards accomplishing goals that make you feel good about yourself, whether that means taking on a new project at work, volunteering, or working out. If you build yourself up, you'll probably gain self-confidence. Being insecure about your relationship or yourself can cause irreparable damage to both.
2. Unrealistically high expectations. You're a human, right? Well, more than likely, so is your partner. Imperfectness is something that comes with being a human, so before placing high expectations on your partner, consider the other things they have on their plate. You may get upset that they didn't come home and clean the house after work, but maybe they had an unusually heavy workload. Make sure that you aren't asking too much from your partner. Ask him/her calm questions to see if you're simply asking too much of them, because humans all have different, individual needs.
3. Selfishness. As said in #2, people have differing needs, so it is important to make sure their needs, as well as your own, are being met. Everyone needs alone time, everyone needs to spend time with their friends, everyone needs a day off. Sometimes the most selfish actions involve spending habits. (This goes for single people, too.) If you aren't living within your means, like eating out, shopping, going on vacation, etc., when you don't have the financial ability to do so, then STOP. Racking up debt instead of being thoughtful about other financial responsibilities is a huge indication of selfishness, because you're taking away security from you partner (and your future-self) to simply satisfy a present desire. This comes around to every day actions, if you do something without thinking about your partner, you're doing it wrong. Make decisions together, ask your partner about their opinion. A little selflessness goes a long way.
4. Not making quality time for each other. The keyword here is quality. I'm still in college and with that comes a lot of time management. I have a full course load, 2 internships, a job at the university writing center, a campus leadership position, and (for lack of a better term) a shitload of homework. Busy doesn't even begin to cover it. When I do get to spend time with my husband, often times we have other work to get done, like take care of our dog, visit our parents/siblings, go grocery shopping, clean, and volunteer. That is time that we get to spend together, but it isn't exactly quality time. Also, time we spend watching tv or working on our projects aren't exactly quality, either. Go out for dinner/dessert or have a picnic with your phones left at home, go for a walk and talk/quiet run, read a book together aloud, play a game, write a song, or just lay outside and stargaze. Do things that enrich your relationship.
5. Ungratefulness. Often in our busy lives, we take our lover for granted. We don't appreciate all the small details and gestures they do for us, but it is imperative that we stop and say 'thank you' for the help they extend or for the sweet text they sent. In order to not take things for granted, if you forget to say 'thank you,' but you remember the kind action, just pay it forward. Do something nice for them in return and tell them that you appreciated that thing they did. It will amaze you how much a returned kindness can make your relationship stronger.
6. Stubbornness. We all have opinions. Many of us have strong opinions, but that doesn't mean that we should ever be stuck in our ways. In some relationships, one or both partners may even be too stubborn to apologize, admit they're wrong, or work on a new solution to an old problem. Even if you think you're right, it is important to swallow your pride from time to time to keep your home happy and sane. Most arguments in my family start out of stubbornness: my dad always thinks he's right, my sister has a rough tone of voice, my mom is dismissive of others. It was a real challenge growing up, but I learned over time that the best way to 'win' an argument is to be flexible. Don't simply throw your hands up (give up), but know when the conversation is past the point of a logical end. Being willing to understand the other person's point of view is the best way to end stubbornness.
7. Being unforgiving. People are people. That's my mantra. You can't expect anyone to ever be perfect or to always do what you want them to do. If your partner says something offensive, do your best to go by Queen Elsa's advice and let it go. If your partner forgets to pick up tampons/clean the toilet/buy groceries for a dinner party/bathe the kids or dog, remember that there is always time to fix that missed action, but scolding them harshly for something may not be so easily repaired, so forgive them. If you do encounter a situation that cannot be forgiven, maybe that is a sign that you aren't with the right person for you, because if your trust is broken and cannot be restored, then your relationship probably isn't going to make it after all. And that's okay. Should you ever have a relationship/marriage that ends, simply remember that your life doesn't end just because your relationship/marriage did. Failure is a event, not a person. If the action is something you can forgive, don't hold on to something that bothers you because it can fester into resentment, which is one of the leading causes of relationship-death.
At the end of the day, we're all working towards being the best versions of ourselves. With the right environment and no self-sabotage, we can all be exactly who we want. Consistently working toward the version of yourself that you strive to be is the best way to ensure success. Happiness within yourself and your home are the keys to being successful in the big, wide world.

