1. Usually, I carry two or three knives in belt pouches since I've lost TWO Spydercos due to lousy pocket clips.
2. Leather and Cordura are preferred with a prefernce for cordura.
3. Horizontal works for me
4. For the ones I carry vertically, the knives go tip up.
e.g. Today's carry, BM 732 in cordura pouch, tip up
SAK in leather pouch
Mini-Grip in Cordura pouch, tip up