Adding Pluses to spells

How do you give spells a +3 or +4 some npc do this is it possible for a character to do this?

+3 or +4 what?

What are you asking? Be detailed, lengthy, and specific.

Do you mean attributes? Superior runes would do that and there are +1 headpieces. You can get +4 in fire with a flame eye and a superior fire rune.