I've seen people on various places on the internet criticize Ranma's disguises. That annoys me because I don't think they are bad. I'll admit that they could probably be improved but given how little time Ranma spent on them they do seem to be pretty good. For instance while pretending to be Ryoga's fiancée Ranma spent little time preparing but she did wear a dress, a wig, glasses, put on make-up (face powder), and spoke using feminine word choices. What more could she really have done except maybe put on contacts so she'd have a different eye color? It's not like he had the time to add prosthetics or detailed make-up work, realistically Ranma's disguises are about the best a person can do given time constraints.
The main reason I view them as being good is because they did what they were supposed to - fool the person that she/he (this is one of the times that English not having a good gender neutral pronoun annoys me) was attempting to fool. The most interesting thing about it is that Ranma himself, in the manga at least, was surprised that it worked the first time he did so. Since it was proven to work he did so again and again. Ninja, the historical spy/assassin type, commonly used disguises to infiltrate and considering how many aspects of ninjitsu Ranma displays him doing so makes sense. The thing is most of the reasons as to why the disguises worked for ninja is because the people who they were being used on didn't know the person in the first place (which is the case for some of the ones Ranma uses). The only person who seemed to always be able to see through them was Akane which is very strange when you consider that she can't figure out Ryoga and P-chan are one and the same when she has been given many clues (such as Ryoga's desire to get the cure) and knows the nature of Jusenkyo as well as anyone else in the series; though it could be an indication to show how she and Ranma are connected (the Japanese have a term for the connection between two people who have been around one another for a long time and can seemingly sense them from their connection to one another but I can't recall it at this time).
That is another thing I have seen that annoys me -when people deride Ranma's disguises I've seen the claim that even the guileless Akane can see through them. What manga were they reading by chance? Akane is not guileless. She tends to be less deceitful than most of the cast members and is generally honest but she has displayed various degrees of guile. Some examples of her displaying guile: Her lying to Ranma's mom about Ranma's identity when he was pretending to be Ranko. Her going along with the plan to pretended that she really was married to Ranma to convince Ukyo to leave. Her convincing Ranma's mother to take Ranma bra shopping as revenge for insulting her. Going on a date with Ryoga for the sole purpose of making Ranma jealous. Lied to Miss Hinako about Soun being married. Akane can be and is deceptive and willing to be dishonest even though she tends to do so less often than other cast members.
Of course if Ranma had bothered to spend more time thinking and planning (he is fairly impulsive) he would have made better disguises or decided a disguise wasn't needed at all. The thing is even if Ranma didn't have a reason to do so or did come up with other ways to do what he wanted to he'd probably still don a disguise. Ranma finds it to be fun to put on a disguise and mess with people, he has even stated that he was enjoying doing so on occasion.
I don't see Ranma putting on a disguise in fan fiction very often and when I do see him do so it is most commonly disguising himself as a sailor senshi or Ranko. This is one of the many things Ranma does in the source material that I just don't see in fanfiction as often as I think it deserves. There are a lot of reasons as to why he would do so and has done so. What in particular I'd like to see more often is Ranma impersonating people in authority for example a police officer or ranking person in some type of organization, heck even pretending to be a secretary to get information on a business/the government would be interesting. I've had an admittedly not put much thought into story idea about Ranma being hired as a political impersonator, thought it would be funny for an assassination attempt to happen only to find that the small caliber bullet used doesn't have enough force to penetrate Ranma's skin (considering the amount of damage Ranma can absorb small arms like those carried by the regular police in Japan and most commonly found on the Japanese black market simply wouldn't be able to penetrate) or for Ranma to impersonate a celebrity because they pissed him off (Ranma is shown to be perfectly willing to mock people like he did Mousse's fighting style by implying that it was just like a stage magicians). While I could see Ranma doing so as a means of identity theft (like Ryu Kumon did to Ranma) those types of fraud I more associate with Nabiki (I keep expecting to see a fan fic in which Nabiki is doing identity fraud and remittance scams, they are far too common in Japan at this time, but have yet to see one even though it is something I find extremely likely for her to do).
Ranma enjoys doing so, his disguises aren't bad considering the amount of time he generally puts into coming up with them (very little), they work on his intended targets and Ranma would make a very good method actor. I was rereading the arc in which Ranma disguised himself as Yoiko Hibiki (Ryoga sister) and if I didn't know better I'd have believed that Ranma was Ryoga's sister, he got pretty caught up in playing the part. Ranma being an actor or into role playing in fan fiction simply doesn't occur very much yet Akane being an actress, going to school to be one, or wanting to be one shows up more frequently than I think it should especially when you consider that at the beginning of the Romeo and Juliet arc she clearly did not want to be one even tried to convince them to chose Ranma instead of her until she learned of the part they wanted her to play (she only wanted to be that one character because of past experiences and had zero interest in becoming an actress playing any other character).
Another thing that somewhat bothers me is that Ranma in fan fiction rarely uses any alias other than Ranko (which I have already mentioned on this blog is not one I find likely for Ranma to use again because of the memories associated with it). In the manga he has used several for example: Yoiko Hibiki and Kew. I would think that more fan fiction writers would think of giving him a different alias on occasion.