I fully believe that everyone should take time to themselves to help improve their relationships with not only themselves but with others as well! I like to take Sundays to myself. This doesn't always mean I get the whole day but I take what I can get! A few things I do for myself on Sundays are:
Clean- I like to take care of any cleaning that needs to be done after the week. For me, this typically includes picking up, doing dishes, and doing my laundry. I try to wash, dry, fold, and put away clothes all at once so I don't see the mess of it on Monday.
Organize- Each Sunday I sit down with my planner/calendar and fill out what I know I have for the week. In college it consisted of writing down my classes, my assignments, exams, etc. Now it consists of meetings, appointments, work tasks, and anything else I have planned that week.
Meal prep- I do meal prep a bit differently than most. Oftentimes people will see meal prep and think of eating the same boring meals for the whole week, right? That's not how I do it. I will make up a couple main ingredients that can be used in multiple recipes. My core ingredients are usually chicken breasts and pasta. The worst part about cooking is how long it takes- especially when you are hungry! If you take 30 minutes on Sundays to cook the things that take the longest, then you will have access to easy meals the whole week!
Shower/bath- I usually prefer to take a shower but once in a while I will prefer a bath. Either way, I make it relaxing and catered to me. No time limits, fully exfoliating, and using ALL the good smelling products. The times I choose a bath I will light candles and use bubbles and bath bombs.
Facemask- I like to end my night with a facemask. I go between clay masks and sheet masks, with different ingredients depending on what my skin needs. If my skin is dry I will use sheet masks with aloe or hemp in it. If I want to exfoliate I will use clay masks. While doing a face mask, I will relax and catch up on my favorite shows.
Try finding time at least once a week to take to yourself and do things that will benefit you. You will see how much your relationships improve. Your relationship with yourself will improve, which then leads to your other relationships improving as well!