"each other" in Arabic changes depending on the subject (we/they). So I'll put a subject in your sentences.
We looked at each other.
(نحن) نظرنا إلى بعضنا البعض
We meet each other.
(نحن) نقابل بعضنا البعض
They respect each other.
هم يحترمون بعضهم البعض
They communicate with each other.
هم يتواصلون مع بعضهم البعض
They (females only) talked to each other.
هن تحدثن مع بعضهن البعض
Hope this helps.