I don't play or know how to play cribbage, but I found the following info.
Cribbage Strategy for Discarding for Your Opponents Crib
There is no such thing as a safe crib, but here are several ways you can reduce the chances for giving your opponent a big crib.
1. Avoid discarding cards that add up to five, a 3 and 2, or a 4 and 1.
2. Avoid giving the Q, J or 3, 4; they often produce runs. J has also a 25% chance of counting one point as Nobs.
3. Avoid two cards with just one between such as Q-10, 10-8 combination as it only takes one card from the dealer to complete the sequence.
4. Avoid 7s and 8s; they are big hand builders.
5. Don't discard two cards of the same suit.
So the good cribbage discard onto opponent's crib is: 10-K, 9-K, 6-K, 6-Q, 9-Q, 8-K, 7-10, 6-10, A-Q, 7-Q, 7-K, 8-Q, A-K and so on
Sometimes it pays to give your opponent something good. If four of your cards combine to make a good hand then, give your opponent what is left over.
Double runs should almost always be kept; chances of a quadruple or triple run are high enough to warrant keeping a double run even if you must help your opponent's crib a bit. An exception would be a hand like 5 5 10 10 9 8, when the best play is to throw the 9 8.
If you need to discard face cards, throwing a king into the opponent's crib is better than throwing a queen or jack, since it's hardest to form a run with a king
When there's a conflict between helping the opponent's crib and keeping your own hand intact, consider the score of the game. If you're ahead and it's okay if you both score big, you might take a chance on giving the opponent a big crib; but if you're behind, you want to play defensively and slow down the game, which means you should give up your own best hand to avoid helping the opponent.
source:
http://www.rubl.com/rules/cribbage-strategy.html