For nitrogen. Use sparingly in hot or cold heaps and mix well with the other ingredients. Pet hair can also be spread out on the grass (make sure the cat is inside) for birds to use (they LOVE it).
I
Ivy.
Absolutely, positively must not be put in the compost. All you need is for one node to survive. Don't trust that the temperature of even a hot heap will rise enough to kill all the plant tissue, not with ivy in any case, it just isn't worth the risk.
K
Kitchen scraps. Mostly suitable for hot or cold heap or wormery. See food wastes.
L
Leaves.
For Carbon. Suitable in a hot or cold heap. You will probably have too many to deal with at one time to put in a wormery. If you want to compost leaves quickly, combine 5 parts leaves to 1 part manure.