When I suffered a miscarriage at 12 weeks, we buried the tiny fetus, along with its amniotic sac, in the garden. I thought of taking it to the doctor, for testing or whatever it is they do with the "products of miscarriage", but I felt strongly that this little being deserved a funeral of sorts, so that's what we did. After that happened, we got back to trying to get pregnant. I know women who light candles for their babies lost to miscarriage in church, and those who have little statues representing their baby. One friend got a tattoo to commemorate her baby, lost at 16 weeks. Other mothers have pendants they wear, to keep the memory of their lost baby alive.
Most of these things (except perhaps the tattoo, because it was a stylized little fetus my friend got) allow the mom to honor her baby in a way that is not obvious to others. Yet, these things give you something tangible by which to remember. Some women will benefit from talking to a counselor after a miscarriage. Many people are not comfortable talking about grief, so your friends and relatives and even your partner may not offer you the shoulder to cry on you need. Grief counselors may be a better option for women who want to work through their feelings about after a miscarriage.