It depends on what you are writing. 1) "After hanging out with my friends.." - then you don't have to say "I met my friend (..) and then I left" 2) Or, "I hung out with my friends (...) and then we went our separate ways" Perhaps you could inform us a bit more as to what you are writing. ^^

If they are very good friends you just tend to say, "OK see ya" It's a very short way of saying goodbye and see you later all in one sentence.

After hanging out with my friends, it was time to go home. So I said goodbye and we parted. [To an English-speaker this does not sound as drastic as it does to you perhaps! It simply means you left and your friends stayed where they were] After hanging out with my friends, it was time to go home. So I said goodbye and we went our separate ways. [Again, this just means you and your friends are not going in the same direction. Imagine you are saying goodbye to your friends on the street. Then you turn around to walk home and they continue walking in the other direction. This is to go separate ways] After hanging out with my friends, it was time to go home. So we said our goodbyes and I left. [If you want to avoid the verbs “part” and “separate”. “To say our goodbyes” refers to the whole process of saying goodbye and wishing each other well]