1. Be slow to push opponents out of 1NT if they are vulnerable. Conversely, strain to balance if they are non-vulnerable.
2. With a known 29 points between you, consider 3NT, even if you have a 4-4 or 5-3 major fit. Playing matchpoints, of course.
3. Strain to make light one-level overcalls with a suit that wants a lead. AKxxx or KQJxx with nothing else is fine at matchpoints (not IMPs), providing your partner is aware that you may only have 6 or 7 points.
4. Strain to push your opponents up or out of a 2H contract. Usually them playing 2H will be a bad board for you.
5. Be slow to make speculative (marginal) doubles of non-vulnerable opponents. Beating them won't be worth the times they make it. But if they are vulnerable, down one for +200 is always a good result.
6. When you are sure your side has nine trumps, generally take the push to the 3-level -- not expecting to make it, but knowing they can make their 2-level bid.
7. If you know your side has 10 trumps, save at the 4-level, non-vulnerable vs vulnerable opponents. If you suspect that your side has 11 trumps, you can save at the 5-level safely, non-vulnerable vs. vulnerable opponents.
8. When opps play 3NT after an invitational sequence, unless you have a good 5-card suit to lead from, lead passively. If you lose a trick on the opening lead, it may be their only way to make 9 tricks. Conversely, if they appear to have bid strongly and have plenty of points, you have to lead aggressively.
9. If 3NT is one of your options and your stopper is Ax (with little likelihood of partner having another high honor), 3NT is probably not a good choice, unless you have 6 or 7 tricks in a long suit you can run immediately.
10. A trump lead suggests that the side suits are not breaking. (Apply this to your own leads. If you know that the side suits are not breaking, lead a trump.)
11. Induce a cover if you can and are missing two honors (say king and jack) by leading an honor.
12. When partner makes a balancing double in the passout seat, bid a 4-card major if you have one over a 5-card minor, as usually that is what partner is hoping you have.