Leviticus 18

In the ending verses of Leviticus, the Lord specifically instructs the children of Israel the do's and don'ts of his commandments.  He commands them -

"After the doings of the land of Egypt, wherein ye dwelt, shall ye not do: and after the doings of the land of Canaan, whither I bring you, shall ye not do: neither shall ye walk in their ordinances.

4 Ye shall do my judgments, and keep mine ordinances, to walk therein: I am the LORD your God.
5 Ye shall therefore keep my statutes, and my judgments: which if a man do, he shall live in them: I am the LORD."  (Old Testament | Leviticus 18:3 - 5)

There probably are some that wonder why the Lord had the Israelites destroy the groups of people in Canaan to occupy their land.  Obviously, these people were ripe in iniquity, their "doings" were an abomination to the Lord.  Nephi logically teaches his people -

"...do ye suppose that the children of this land, who were in the land of promise, who were driven out by our fathers, do ye suppose that they were righteous? Behold, I say unto you, Nay.
34 Do ye suppose that our fathers would have been more choice than they if they had been righteous? I say unto you, Nay.
35 Behold, the Lord esteemeth all flesh in one; he that is righteous is favored of God. But behold, this people had rejected every word of God, and they were ripe in iniquity; and the fulness of the wrath of God was upon them..."  (Book of Mormon | 1 Nephi 17:33 - 35)

A few of those abominations the Lord outlines are -

Incest

"None of you shall approach to any that is near of kin to him, to uncover their nakedness..."  (Old Testament | Leviticus 18:6)

Adultery

"...thou shalt not lie carnally with thy neighbour's wife, to defile thyself with her."  (Old Testament | Leviticus 18:20)

Homosexuality

"Thou shalt not lie with mankind, as with womankind: it is abomination."  (Old Testament | Leviticus 18:22)

The Lord warns -

"Defile not ye yourselves in any of these things: for in all these the nations are defiled which I cast out before you..."  (Old Testament | Leviticus 18:24)

The warning then, even to our generation, is that when we become ripe in iniquity, we too may lose the blessings of this land.

There are a couple of do's that I wanted to include just for my own reference -

"Ye shall keep my statutes. Thou shalt not let thy cattle gender with a diverse kind: thou shalt not sow thy field with mingled seed: neither shall a garment mingled of linen and woollen come upon thee."  (Old Testament | Leviticus 19:19)

I believe the Lord is suggesting that we avoid mingling the doctrines of men to the doctrine of God. 

"Thou shalt rise up before the hoary head, and honour the face of the old man, and fear thy God..."  (Old Testament | Leviticus 19:32)

Just as a matter of honor and respect, we should always stand or rise up as we meet and great the elderly.