Making decisions is a process known in the Catholic Church as discernment.
Discernment basically means, first of all, identifying the decision to be made. Then you would spend some time gathering the necessary information to help you make an intelligent choice. Thirdly, once you have all the info you need to make an informed decision, there needs to be a period of prayerful openness to God’s will for you. Alongside placing your decision in God’s hands, you would need to take some time to weigh up the pros and cons. Finally, you would ask the Holy Spirit to transform your thoughts and desires and guide you towards the truth. Ultimately, you should finish by actually making a decision, based on full knowledge and trust in God.
This can all be easier said than done, but it really is about allowing God to be a part of your choices and thoughts.