If you are in a relationship, is it what you always dreamed about? And why should you only celebrate and demonstrate your love on just one day of the year?
The problem is, that after a while, you take each other for granted. It doesn't mean that your love for your partner is fading, it simply means, that there is a lack of effort that can have consequences.
And - it doesn't mean that your partner has to fulfill all of your needs and the other way round; be realistic - no one will ever be able to do that. 
A day like valentines day is a reminder of how important it is to show each other how precious the time is, you spent together. It gives us a chance to be proactive and show gratitude, and of course this can be any day, not only a random day in february. 
Here are some short and simple ways to do so. In my opinion they are very important.
1. Accept your partner just as they are.
He or she is a special being, with their own wonderful traits and unique gifts. Learn to appreciate the full package. Whatever they do, think, say or make, it ultimately makes them who they are. They are entitled to their own decisions.
2. Always be in integrity.
Tell your partner the truth, unconditionally, because honesty is the key of a good conversation. Trust can build a zone of safety and comfort with each other.
3. Get clear on what you want from the relationship.
Make the fulfillment of your short term and long term needs the criteria for choosing a partner and being in a relationship. Create and share a vision of your dream life together.
4. Resolve your differences as soon as they happen.
Conflict gets difficult when it doesn't get solved right away. The sooner you stop blaming and start talking, the better you feel. Never go sleep with an unresolved issue.
5. Let go of the past.
All relationships have their difficulties. Remember only the lessons learnt and forget the details. Weather the stormy moments, and savour the memory of sunny days. Remember what brought the two of you together in the first place. What attracted you to each other? What do you admire about your partner’s personality?
6. Have fun dating your partner regularly.
At this special date, putting each other first helps a lot. It will water your relationship like a plant, so it can grow.