The ultimate considerations
I've only considered some methods, others are totally out of the way.
Poisons/Chemicals (e.g: KCN, Rodenticide, Arsenic Trioxide, Chlorine, Hydrochloric Acid [concentrated], Alcohol Poisoning [>70% alcohol concentration])
Commom household chemicals contain enough toxic substances to be lethal but more often than not they are mixed up and are mostly acids, which are gonna hurt a hell lot when it burns your alimentary canal after ingestion. Desirable substances that are known to be one of the "best" methods, like KCN (Potassium Cyanide) are extremely hard to obtain. Hence for 12½ years olds like me, drop the idea.
-not too sure about minimum lethal dosage
-obvious as suicide (concerns regarding insurance)
Jumping/Falling from height (building, bridge... anywhere higher than 46 meters on land and 76 meters on water will do)
-obvious as suicide
-affect house prices (if it's from a HDB flat)
-may cause trauma to passersby
-poor police clearing up my mangled body (they probably don't give a damn about bloody scenes anymore since they have seen so many cases of such stuff but to counter the belief of "selfishness", I would like to spare a thought for them)
Hanging
-might be painful and high risk of failed attempt, if not done properly
-might end up brain dead if rescued before ultimately dead
-I heard it takes really long
-I don't know where to hang from... someone suggested doorknob. I don't have a ceiling fan
-rope snapping... I'm fat
-how thick should the rope be?
-what knot to use&how to tie it?
-hanging corpse is a horrible typical suicide pose
-house price gonna drop ( I don't know where else to do it other than in the house... the woods? Yeah. I've considered it before, from a tree. Credits to The Hanging Tree and Aokigahara Forest )
-I'm scared to go alone into the woods
Exsanguination (bleeding to death)
Hell yeah I actually like this but I'm a chicken person I will faint if I see so much blood... cut wrist or cut throat uh
-slow
-painful
-hell low success rate
-typical teenage attention-seeking behavior if I live
-bloody blade is slippery and hard to hold on to
-horrible bloody scene for family
-again, if I do it at home, house price will drop
-obvious as suicide
Drowning
***CAN BE MADE INTO AN ACCIDENT***
-painful [lungs will first feel like it's on fire]
-pretty slow, a couple of minutes of torture before slipping into tranquility
-I don't want my body to be found, so I want to sink I will need to hoard rocks and heavy things to the sea
-more convenient to do it at home, but gonna be obvious and house price~
-if fished out early corpse will be OK but... if I'm going to the sea then... I will be a bloated up balloon
Pills
-low success rate
-attention-seeking feat, as with wrist slashing
-takes a long time
-gonna be found in the middle of puke
-lethal pills like barbiturates are hard to obtain
-needs additonal methods combined (i.e. plastic bag, alcohol,helium)
-apparent suicide
-house price...
Strangulation/Suffocation (Apart from hanging,which I've already mentioned)
Plastic bag
-hard to make it airtight
-must be combined with other methods
-survival instinct>I will thrash around subconsciously and even if I'm unconscious I can rip the plastic bag off my head
-might be found before dead
-apparent suicide
-house price
Helium
Where the hell do I get a helium tank and how does the friggin thing work
Vehicular Impact
***can be made into an accident***
-no use thinking about trains, now all MRT platforms have safety barriers
-getting driver into trouble for nothing
-high chance of ending up in the hospital crippled instead of the morgue
Ok... This is about it. I've thought about murdering someone or smuggling drugs, then getting the death penalty, but few kids are executed nowadays plus I don't want to kill people and I have no idea where to get hold of drugs.