With practice, people with other attachment styles (anxious, avoidant, or avoidant) can unlearn their those behaviors and develop secure relationship styles. It is possible to change your relationship style with a little effort. 

Focus on Personal Boundaries

Focusing on personal boundaries is one of the best ways to develop a secure attachment style. Boundaries can involve how much time you spend with others, issues regarding money, or standing up to abuse. Developing boundaries helps you become more confident in your relationship with a little work.  

Practice Effective Communication

Communication is critical in a secure relationship style. When communicating, learn to listen, and be compassionate. Share your emotions and make an effort to understand those of a partner. Take responsibility for your actions and take an active role in creating solutions. 

Being vulnerable and sharing your feelings can be difficult, but it helps to bring real issues to the surface so you can solve your problems together. Be direct and speak with empathy. 

Take Time For Self-Care

You need to have a healthy relationship with yourself before you can form strong and long-lasting bonds with others. Don't neglect your physical and mental health. Make sure to take the time to understand your personal needs, wants, and values. 

Once you learn to care for yourself, you'll be in a much better position to be with someone else.