Tips or Tricks for improving Cervical Mucus

According to OPK's I ovulate every month however I never produce any Cervical Mucus... Im not currently taking any medications that will interfere and my diet is Fair... any Tips/Tricks for improving Cervical Mucus??? I know I can use pre-seed but I would prefer to have EWCM so i can pinpoint my ovulation date without having to buy the OPK's every month