I am naturally an introvert, but the Lord used my job and my situation (a new baby) to motivate me to find the great group of mom friends that I have today. Only a few of us in the group are Christians, and I believe are in the lives of the other women for God to do a mighty work. My best piece of advice, one I don't follow too well at times, is to be transparent. Allow yourself to open up and share, and others will share too, and the relationships will be better for it.