Strategies for Pegging

General Strategy

Look for combinations of cards already in your hand, relying on the cut card can backfire hard.
Don't focus on the Go unless you are at the very end of the game and it is close. Pegging usually scores more than the go so it is key to keep it consistent.
Keep pairs and triples together if possible, but don't get stuck on them if you have better.

For your hand, focus on those combos you have, it is never a good idea to try and go for runs if you don't have them or to go for flushes. This can end up with you having a horrible hand.
If you have two combinations that are equally good but don't work together, put the cards that fit into other things easier, as in lower cards, fives, and face cards first as they can work best in the crib. The hand is usually more refined than the crib as you can see if so shoot for more points there.

The Crib is mostly luck of what is put in it so relying on the crib for points and throwing out a hand is a bad idea unless you have nothing in your hand.
The best things in cribs usually are lower cards, fives, and face cards as they have versatility.