1) Use only public key authorization for SSH or 2) Use VERY STRONG passwords 3) Have a long limit between password attempts or 4) Have the computer blacklist any IP that tries to log in unsuccessfully more than X times (where X ~ 10) 5) Have SSH running on a non-standard port. This will deflect the majority of automated attacks but will not stop a dedicated attacker. 6) Use port knocking or the technique described to allow only users with some knowledge of the system to be able to talk to the SSH service 7) MONITOR YOUR LOG FILES. An attacker should not EVER be able to brute force passwords for a few days without YOU noticing.
Now you are free to layer as many of these as you need and each will reduce the probability of a successful attack, but you need to take into consideration the cost vs risk. For example the technique described in this article offers added security but places limitations on connecting to the machine (from a client that has the right algorithm, with synchronized clocks, and also make sure not to make a mistake otherwise you'll get locked out for 15 minutes which can HURT if you're dealing with a critical matter).
Personally I like the concept but I think the added costs are too great and compared with using some of the other security mechanisms.