Well i think it would depend on the pants, there are alot of different styles of cargos. I googled it and found a few things :P

I definitely think you can pair them up with wedges! It will give your look a girly edge without looking too girly... And No doubt about the flats (:

I'm not really sure on outfit ideas though since I'm not sure what style cargo ... Sorry!

If I were you ,I would prefer to wear chic cargo pants with wedges .The match not only make you look more fashion also in the chic-edge!

If you still uncertain you can comparing by yourself !

Both flats and wedges can look good.But that depends on style. Can you post pictures?