I recommend that you should apologize to the other right after you find yourself to blame if yo want to keep the relation good for the future. (if you want the relation to go smoothly in the future.)
「もし自分に非がある場合、すぐに謝罪した方が、今後の相手との関係も円滑にすすむ」
勧める recommend that ~
相手に謝る apologize to the other
～するほうが、～したほうが should ~
(had better ~は表現が強いのでここでは相応しいと思わない）
～する後すぐに right after ~
自分に非がるとわかる you find yourself to blame
もしその関係を将来円滑に進むと思うならば、
if yo want to keep the relation good for the future.
(if you want the relation to go smoothly in the future.)
I recommend that you should apologize to the other right after you find yourself to blame if yo want to keep the relation good for the future. (if you want the relation to go smoothly in the future.)
日本 
