Shole link wrote: Really the only thing you should avoid is the things that you dislike. For example if you like romance don't read a romance manga 😃
Other than that, so far i didn't come across a terrible manga.
I believe that is sensible and logical advice, however it is worth noting that sometimes we might miss something good if we don't give it the opportunity for being in a different genre.
I think pretty much the majority of people try to stay within their comfort zones, which means reading the genres we already know we enjoy. Still even within our zone - or perhaps because we have read enough material of the genre to start noting patterns and tropes - we might find that there is some manga that is actually lower in quality than the rest. For example, a maga made not to tell a story but to exploit the genre formula without caring to develop the characters, have logic or trying to understand why the things it is mimicking worked for the other mangas of the genre.
Pokemon reBurst is a manga that tries to bring a darker pokemon story but tries at the same time to cash in the shounen side. To the point where it doesn't dig deep within its franchise roots and it becomes pretty bland for the melee one. Unless you're willing to be open minded to accept Pokemon and human fusions a-la-digimon, tons of fan service, not real exploration on the game's setting or simply never cared for or heard about Pokemon. Good luck anyway, because the response in the west was so bad there even isn't a solid fan translation of all the episodes so it is hard to come by.