Tropes and Cliches

Sibling Tropes: In general

So we all know some one with a sibling or two. Or you are that person. Siblings can be great: you learn stuff faster, a half way decent role model, a built in best friend some days, etc. But there are people who write siblings, but don't have any and never been around those who do. Like siblings that get along all the time is not necessarily normal. All siblings fight every once in a while. Siblings can have a falling out, hell there are siblings who are basically the backup parental unit. I found list of sibling tropes, but I just want to get you started on writing siblings.
So what is so bad about sibling tropes? Well...the siblings are either so close you have to question their relationship or they hate each so much that they are willing to carry a grudge until they die and regret it...looking at you Sasuke Uchiha. Not to mention there is the Sibling Love Triangle thing I mentioned earlier on in this book. 

Now how does one write siblings? Looking at a cultural stand point, it can really depend on many things. In some cultures, everything falls onto the eldest sibling. In most Eastern cultures, the eldest is normally the "example child". Every success and failure is always brought up at family gatherings. Again, looking at Sasuke Uchiha, he was compared to his older brother for years, and then he killed him out of revenge for killing their entire family only to find out it was a ploy to get rid of the Uchiha without getting their hands dirty by an asshole called Danzo. The younger sibling may not be the best at sports or academics but give them a crayon and they will give you a master piece.

Or the obviously favorite child. Now most parents will say they don't have a favorite, but they do. Normally it's the one that stays out of trouble. There is the spoiled sibling who is 9 times out of ten is the youngest (who is most likely a girl.) The lone gender child who is the only boy or girl out of their siblings (see The Loud House for reference).  The polar opposite siblings; half siblings who are either from another marriage or relationship or a result of modern medicine in vitro fertilization; non blood related sibling ( could be a stepsibling or adopted), the list goes on. Then there's the ever popular sibling rivalry, which could be healthy when it comes to trying your best. But some of the time, parents push things too far to the point one of them snaps. 

Even the sibling age gaps is important when writing. Are they Irish twins ( born within 9 months of each other or the same year...not sure which) or is one of them a few months shy of graduating high school while their sibling literally just got out of pull ups. 

Give them different and similar interests.  They may be siblings, but they are separate entities. Especially if they're twins or part of a set of multiple. Nothing burns my soul more than seeing twins/triplets/etc. with similar names and dressed alike.  They can like comic books but can like different genres. Or like sports, but one liking the athletic stuff and the other liking the...technical stuff...I know nothing about sports, I have cousins for that.
Gender of siblings can be tricky to do. One being due  to the idea of writing the opposite gender authors would enforce gendered sterotypes, and often more than not can't be real. A girl raised around three brothers might not be in any way boyish, but have basic knowledge of how to fix a car until you can get to a shop. A boy raised around five girls may not be feminine, but understands what most females go through during that time of the month. 

How do the parents come into play? Well, in my experience, most of the rules go out the window with younger siblings. That or each sibling have a different set of rules outside what is established by the parental unit. What that means is outside of the main rules one sibling is not allowed to have anything with sugar after 6pm due to it messing with their meds.

Love, hate; frustration, satisfaction; cold-hearted assaults, warm support; distance and closeness... this is mix can be found with all siblings. It depends on the individual personalities of the siblings in question what the ratios are. That's basically it.