You can choose one main item and several sub-items in different categories to boost your character's stats. Take note of the cost of your items. You will begin with 20 points in each category, and can get more points that can be allotted as desired in all categories. Save your points until you determine what equipment you have and where the biggest costs are. There is a 60 equipment piece limit. Sacrifice extra items and those with the worse stats to improve other items. Consider only improving the rarest and best items in our possession. Do this with one in each category; you will always get better items as progress and open chests. Only sell items for money when absolutely necessary so you do not miss out on item experience.