There are a couple of things to keep in mind. First, kisat dur is most effective against humanoids. The idea is that if you disarm your opponent, they have no skill in hand to hand and you will wipe the floor with them pretty easily.
However, also keep the techniques of nabusuthar (divine first) and sodel ar (shield of flesh) in mind. With nabusuthar, if your observation is high enough, you can detect what technique your opponent will launch and interrupt it with sodel ar. Fertharnas (the beast slayer) is also aimed at fighting beasts (obviously ;-) ). Keep your distance and allow *them* to close the gap. Because beasts have no armour, scratches can open arteries. Once you have opened a major artery, you have won and you can simply keep your distance until they bleed out.
Against smaller opponents (like a kitten), you really have a massive advantage (literally). To perform Aknunakith (hawkwrath), injur all of the feet of the opponent. At this point you can create space and then launch yourself at them. They will not be able to dodge effectively. A single application of this will likely end the fight entirely.
One last one, (and I can't remember the name) that is *really* effective against beasts is the fact that they have limited numbers of weapons. For a kitten, it is bite and scratch (with one of the 4 paws). Even if you can't use nabusuthar (because your skill is too low), you can look at those 5 potential targets. The one that is easiest to hit for you, is the one that they are using to attack you with. Intercept with sodel ar. With a small opponent like a kitten, the fight is now over, because you can simply throw the opponent. This will stun them. Use charge attacks to follow their flight path and they will likely be dead before they hit the ground (use the advantages you have for *not* wearing armour!!!)
Larger opponents are more dangerous because you can't throw them. The key is always to think defensively. Create space. Let them close the gap (as with fertharnas). Use zimeshabod (phantom strike) to position yourself advantageously. Take opportunities to use stot abodstuton (surprise gut strike). Once the opponent is nauseous, you have won because their speed is half and you can now intercept every single attack, while still attacking yourself.
The best thing to do is just go out in the wilderness and train. At first you will pick up lots and lots of scars, but eventually you will learn how to defend yourself. One quick tip, which I'm not sure is in this thread is that when you are doing wrestling moves, press comma, not period, to wait for it to have effect. If you use period, you will be standing around like a sitting duck most of the time. The only time you want to use period is if you are waiting for them to bridge the gap (and even then I tend to use comma so that I can respond in the exact tic that they are in range).