Spells that require "special" handling

Question

Most of the spells learned in Hogwarts are a simple flow of:

• Choose your spell
• Point your wand
• Say the words
• Magic happens

But there are other spells that specify the need to do more than that.

• For Expecto Patronum, one must think about a happy memory, and even if that might sound an easy task, it is still described as one of the hardest spells, one that even grown wizards are unable to perform.
• For Avada Kedavra and Crucio, one must have malicious intentions and want to hurt one's victim.

What other spells require more than just words?

Answer 1

There is always more to it. If it were simply a matter of pointing the wand and saying the words, then anybody could casts spells. (There would be no squibs, for instance, and any muggle could be taught magic.) Nor would some spells be more difficult than others, if casting them were purely mechanical processes.

The books do not delve too deeply into what exactly a caster needs to be doing or thinking when they are casting most ordinary spells, but there is certainly something additional needed. The additional requirements for specific examples mentioned in the question were discussed in the text because of their relevance to the plot and because they (presumably) were more difficult than typical spells. what precisely—specific wand movements, styling of the spoken incantation, or a certain state of mind—is needed for particular other spells is not explored, but there was always something.