The last four don't need to have any specific item, they just can't be holding an everstone.
It depends on which Pokemon you want to evolve. Some common ways to evolve include leveling up until you reach a certain level, using an evolutionary stone on the Pokemon, and trading (sometimes the Pokemon has to be holding a special item).
Seadra holding a dragon scaleMachokeKadabraClamperlDuskullFeebasGraveler
you can evolve a clamperl to a huntail by trading it ween it is holding deepsea tooth or you can evolve him or her by trading it with deepseacale to a gorbiss with is a ex-treame ly rare pokemon!
Some Pokemon evolve just by trading. Others need special hold items like for example, Seadra needs to be holding a Dragon Scale and then be traded over in order for a Kingdra to be obtained. And Clamperl also needs items like the Deepseatooth for Huntail and the Deepseascale for Gorebyss. Then, if it is traded over, depending on which item its holding, it will evolve ino that certain Pokemon.
Feebas will only evolve through trading it while holding a Clear Scale.
No they evolve after trading while holding king's rock
you evolve scyther by trading it when holding a metal coathe evolves when you trade him with a metal coat
Electabuzz can evolve from holding it and trading it with it holding Electrizer. But the other person gets Electivire.
Depends what kind of pokemon. Most evolve by leveling up, some using stones (firestone, moonstone, etc) some by trading, and some by trading holding a specific item.
Rhyperior doesn't evolve, but you can evolve a Rhydon into one by trading it while its holding protector
It doesn't evolve by level, but rather, by trading it while it's holding a Metal Coat.
Yes, he can, by trading him whilst he is holding a king's rock.