It is so difficult to practice upon subhanAllah.
Maybe I would find it easier to practice if I know I was at fault somehow, or there was a misunderstanding which I could address, or any other valid reason why someone might not be on good terms with me.
There are certain relatives who are very awkward, for no apparent reason, and it is hard not to dislike them, lol. However, being polite and courteous whenever meeting with them goes a long way, they can't complain about anything on your side. It's best not to feed the fire, if they're being rude, just quietly walk away.
I admit, I only apply that to someone older than me, if it is a cousin my own age, they get as good as they give - and I know I shouldn't do that.
It is hard however, to maintain that conduct a Muslim should have with others. In'sha'Allah, it's something we can all work on and improve.