Make sure you are ok first- We all have things we need to do to look after our own health and wellbeing- if that's going to the gym after work, going to bed early to read a book or write in your diary- try to keep this up so you're taking care of your needs first. Then you will feel equipped enough to help your partner.
Offer your partner your undivided attention at some point in the day- Listen to them, don't feel the pressure to respond to them- just let them have their say. Keep eye contact and ensure they know you are listening to them. So many arguments occur when one partner thinks the other isn't interested in them and their day.
Take a moment before you talk to your partner- If you are in an awful mood- try to keep the conversation to a minimum or you could end up taking your negativity out on them and it's unfair when they are not the cause. Then you can talk when your dark cloud has lifted.
Give your partner the benefit of the doubt- It can be tempting to think that they have done something to deliberately hurt you but chances are they haven't. Before you make a decision as to their motivation- ask them and consider the other options. Their actions and words aren't always negatively driven.
When you are angry and it's because of your partner- Take a deep breath and wait until your anger has subsided then address the issue. No good comes from pursuing a dialogue with your partner when you are fuming.
Figure out how to calm yourself down- If you need to take a walk, scream into a pillow or punch the couch to let off some steam- do it where your partner can't see and then approach them once you're not blocked by an angry fog.
Ask them to be honest with you- If they feel you are neglecting some part of them or your relationship- ask them to tell you- tactfully of course- but it won't get fixed unless you're both aware of the niggle. And you should expect the same in return.
Look inwardly- Usually when you pick fault with your relationship it's a reflection of how you feel about yourself. Look to you first and decide if it is your partner who is causing you some angst or if it's down to a personal feeling, insecurity or bias.
Think about the things you do for each other- Your partner may be an all-rounder in your mind- but try not to forget that you have a role in the relationship too and remind yourself of all you do for your significant other. You are both integral to making it work- not just one of you.
Be vulnerable with each other- Sometimes when you're holding back an emotion such as sadness or worry, it can be communicated as anger or frustration, so rather than masking it as something else- let your partner know if you need a good cry or you're anxious about something. Any misrepresentation of your feelings might push them away just when you need them to be close.