Don't be at his beck and call. Make him wait for you sometimes. Men like a challenge. Don't be easy, make him work for your attention. DO NOT be clingy. That is the very best way to lose him. You have to give them their space. Good luck.
"When a woman is able to grow and mature to a point where she is no longer a slave to her own worries, insecurities and fears, then she can finally look past her own wants/desires/fears and see the man?s." In other words dont be to available for him. Don't put your eggs all in one basket! If he wants to see you at last minute when you already have plans, keep those plans and make him wait three to four days. Do not be needy or he will take you for granted or even worse break up with you. Be independent! Learn how to make yourself feel good rather than relying in him for attention all the time to feel better. If you love yourself you wont always need a mans attention.