I think it is more successful when it is not mutual dislike keeping the lovers apart but mutual distrust. If they actually hate each other, there is a problem. Either the hatred is valid, in which case it's hard to have them get over it without making them seem cold and shallow, or it is based on a misunderstanding, in which case having them persist in it makes them really stupid. Tricky.
I think that a difference in morals can also be an effective and realistic thing keeping two characters apart, though there's often some fear/distrust in there, because someone with different morals than you, and maybe also belonging to a different political faction that you, legitimately can't be trusted to do what you would do in their position. This is not a misunderstanding, and also not as extreme as hatred.
Bad first impressions, or excessively good first impressions followed by a worse impression that creates a feeling of betrayal, are a variant on misunderstanding that may seem less stupid, though maybe also overused.
One of my story set-ups goes like this:
Character A sets up a plan to trap Character C. Character B is friends with character C and considers A attractive. Character B charms Character A. Then Character B foils A's plan to trap C. A feels betrayed by B, while B feels that he/she did A a favor by preventing A from doing something that would have been both spiritually bad and strategically ineffective. B decides to apologize with a gift that supplies most of what A hoped to get out of trapping C. But A is furious at B and not only won't let B apologize but insults B badly. So now B is also furious at A, even though both consider each other attractive and have some fond memories of the part before B interfered with A's plan.
Another of my story set-ups runs along lines that are similar but not quite the same:
Character A is a high-ranking person who has delegated to a servant the task of hiring someone for a special job. Character B really wants the job and feels that he/she would be the best qualified to help Character A in the role of the job. But the servant's method of screening job applicants disqualifies B on the first step, and B thinks that the servant is making a serious mistake in what they are looking for in a candidate, in a way that is going to result in A being hurt.
So B goes directly to A to complain about the way the servant is handling the job search. A is in a bad mood, very unimpressed with B for not going through proper channels, and casually says that it's obvious why the servant rejected B for the job. B, who has some self-confidence problems, takes this as a very personal insult and storms out, thinking that A clearly doesn't deserve the help B wanted to give A. A pretty much forgets completely about B until A's only good friend, C, becomes friends with B and tells A he/she should apologize to B. This makes A mad at B for stealing/corrupting C. Again, a situation has been achieved where A and B are angry at each other, though in this case B thinks A is attractive but it hasn't yet occurred to A that B is attractive.
