Question about skills

How high can u get your skills.....its weird like some weapons stack, and some items stack...idk how people get like +18 skills and stuff...

Glyph of Elemental Power gives +2 to the next elemental spell you use, so use that with a helm & a superior rune to get +18. You can use a +1 staff wrapping for a 20% chance of increasing it to 19. Those're the only ones I can think of.

In Cantha, you can visit one of the statues to get a +1 bonus to one of your attributes. So theoretically, with 12 in fire, +1 helm, +3 rune, +2 elemental Power, +1 staff, +1 god's blessing you could hit 20, though you would have to be lucky enouth to get your staff wrapping to kick in right after Elemental Power.

Head Piece +1
Superior Rune +3
Weapon +1

This is pretty much what you can have so far as I know.
Well, this and other spells that affect it.

vinegrower said all you need to know if you're looking to get the highest possible points in your elemental attribute. Twenty points is only possible with elemental attributes (when lucky with a +1 20% and Glyph of Elemental Power) and curses and blood magic (much easier as Awaken the Blood doesn't last for only one spell).