1) Plot or Characters (if it's a slice of life, plot obviously doesn't matter)
2) Critical reception (if available)
3) mangaka or similar series to it (via the recommendation here)
4) Art (bad art won't discount me from reading it unless it's unfollowable art, now that's an actual problem)
Then, if the criteria seems to work right, see if I can rent it from the library first. Nothing will ensure it's correct other than actually reading it, all I can do is try to weed things out.
Genre and demographic - the reason why 80% of my collection is shoujo.
Sometimes, i buy manga because because it's very cheap rather than being interesting. Like Hissing vol 3 was like $1.99, except they BN gave it to me for free, it happen to be boring, yet interesting.
With bargain books, you care more about quantity than quality, while, with normal in-store and online shopping, you select fewer, but more of your taste.
Now, there are some that wasn't my choice, some dude just keeps throwing them in the trash, yet it still happen to be in good condition afterwards. The first time, i didn't like what was in it, while the second time i got Clamp manga in French. D: WHERE IS ROSETTA STONE WHEN I NEED IT?
Read one chapter, if it's good read another. If it's not, go to the next one in order of popularity. I just use manga reader and manga fox's popularity ranking. If a lot of people like it then it's usually good (Hopefully).
Sometimes I use genre if I'm in the mood for something ;)
Mainly cover art and occasionally genre. I'm not too picky about what I read and watch. I don't really care to read the synopsis because it feels like a spoiler. I like to just dive in and read on, getting a feel for everything without any prior information on the story.
First I search through genres looking for anything that has romance that's not josei or shojo and has been recently updated, then I read all the plots to see if there is one that sounds really good then if it's completed I scan through that last chapter to see if it's good, if it's new I start reading it from the first few chapters, but if it's on-going I read comments about it and see what other people think about it and read it depending on whether the reviews are good or bad. Sometimes I read manga if I saw a really good anime and there's a manga adaption though
the genre has to be something i fancy (although there are/have been exceptions)
also the art! the art is a huge part of it, if i dont like the art then chances are im not going to stick with it because manga is obviously ALL art.
There are various factors and I often choose manga for different reasons. I some times ask for recs, sometimes seek out manga from a particular author or sometimes for a particular theme/genre. I haven't actually read that much manga so I think that probably sums it up.
Well I really love shoujo and magical romancy mangas.. but also decent art and if the summary sounds interesting ill give it a try.. thats pretty much it... *bonus if I can relate to the story though* so I enjoy school life to sometimes..
I look if it's completed and not rushed or discontinued, demography, cover (not necessary art, you just can say a lot about some manga just with cover), type (no OEL for me), mangaka, rating, how long it is (I prefer longer, but not too long either), story, then I preview it in case I wouldn't like it (I usually read a bit of second or third chapter), read a few comments with the lowest score, art.
but some manga I want to read are those when I see some images of it somewhere and they are good. like in "name that manga" thread, funny pics on net, or avatars and such.
I don't find all manga (whether I actually read them or not) through different ways, be it randomly showing up on someone's profile (in that case, an interesting title is important), reading about it on the net, through a mention in a recommendation or finding it among other works by an author whose works I like.
Whether I decide to read it depends on the description, but even if the plot is nice, I'll check for the genres, e.g. if there are ecchi elements I'd avoid it in the end.
First I google, 'best Seinen manga' or 'best comedy manga' depending on what genre I want to read, then I go through the results on various sites, then I select the most recurring titles, which I have not yet read. After that I read reviews and summaries of those manga, and finally I select the manga which fits best to my taste.
Genre. what im interested in first.
See the popularity if its good or not. usually if its popular its good because we fellow manga readers have similar minds.
Then read reviews to confirm.
Read the first 5 chapters. Not good then drop.
To be honest I really only read mangas with good artwork. And when I'm reading shoujo, I go for a manga with a single love-line .And with single love-line, I mean a story with one guy and one girl. I simply hate love triangles. Even though I'm a girl, I prefer reading Shonen, so I don't read that much shoujo.