Illusion-keep casting muffle any where you go
Conjuation-buy a horse of shadow mere and keep casting soul trap on him
Alteration-find a pond or lake and keep casting water breathing
Restoration-Join the collage of winter hold and on the last quest go to labarinthia, find the spell tome equilibrium in the first room on the table then cast fast healing and equilibrium very where you go You can also find telakaniss
Sneak-go to high horathgar and unequip all wepons/spells and Neal behing them and keep punching them
On/two handed and bow buy a horse or shadow mere and buy conjuring sword/battle axe/ bow and keep firing at the horse.
Smithing buy a ton of iron and leather strips and keep making iron indigots you can get theses also from the blacksmith glitch and the dawguard chest
Ps is I haven't done destruction or the rest of the skills because there's no fast way of leveling up that skill you just have to level them up naturally.