If you want to make friends requires time energy, unselfishness &thoughtfulness ..time means taking time to spend with people and know about them ...energy is that when you spend with people where you could feel you would if spent otherwise ...unselfishness is going to help others who are in need , immediately , unmindful of self interest ...thoughtfulness is remembering and wishing on their birthday or enquiring about them or their family members .suppose if one person told you his father not well next meeting remembering and enquiring the same will be appealing to the person and in turn, will remember you for lifetime for your thoughtfulness