I don't know what "making convo" is.
If you are shopping with someone and you are done I think you can try asking him what is he looking for, if he says he is done then you can tell him that you are done too.
Regarding phonecalls what I do is wait for a pause and say something like "well, I hope you ------- , see you soon", I don't know if it's the same at your country, try listening how do your family end phonecalls, also look if they change their voice tone, here we change it when saying good bye, at least in my family, I will try to pay attention to another's one conversation to see if they do the same, I've never thought about it. Ending phonecalls isn't easy for anyone, sometimes my mother has to try it many times because the other person doesn't want to stop talking. You can also use white lies, sometimes when I'm at the cellphone I say "well, I'm running out of credits/battery, see you later", or if its close to dinner time you can say "sorry, the dinner is ready, I've got to leave, see you soon" or maybe "I've got another phonecall" or "Someone arrived, I have to hang up ".
Also if you invite someone to your home and you don't want he/she to stay until night you can tell him you have something to do at 6pm for example, you have to say it while you are inviting him, not at 5:58 pm, so he/she won't feel kicked.