Long-lasting relationships aren't instantly formed; they are cultivated over time. You can't instantly walk into a successful long-term relationship, but you can nurture one into existence. If you're trying to turn a good short-term relationship into a great long-term relationship, you'll need to put in effort to make it work.
There are three big secrets to long-lasting relationships, and if you follow them with the right partner, you'll set yourself up for a lifetime of happiness:
Respect. First and foremost, you need to respect your partner as a human being. He/she isn't a toy, he/she isn't a tool, and he/she deserves respect. Value your partner's feelings and do everything you can to give him/her what he/she needs.
Communication. Communication can solve problems before they become problems. Instead of burying your feelings or rejecting the feelings of your partner, create an atmosphere where both of you feel comfortable discussing things openly. If you can address little issues proactively, you can avoid the onset of larger problems that could come your way in the future.
Spontaneity. Relationships need stimulation, and that means trying new things together. Some relationships fall apart simply because they've fallen into a predictable rut, and neither party feels enriched by the experience even longer. Make a commitment to trying new things together and enjoying new experiences.
These three secrets aren't the solution to every problem, but they are important elements in any long-lasting relationship.