How can i make my vagina tighter?

You really can't.: You really cannot make the vagina actually "tighter" without surgery. Especially after childbirth, the entrance to the vagina is more "loose" than it was pre-babies. Whay you can do, however, are kegel exercises which strengthen the pelvic floor musculature. This helps prevent urinary leakage, and also if you flex those muscles during intercourse, the vagina will feel "tighter" to your partner.