Nukitsuke is probably my least practiced cut. I'm not fond of cutting with one hand but that may change as I improve and it's something that needs to be learnt. You're never going to be good at something if you refuse to practice parts of it simply because you're not very good at it to begin with.
Having said that, you need to be careful as if performed incorrectly this cut can actually be quite hazardous. If you have the wrong angle, you don't move the saya backwards enough or if you simply pull the sword out as fast as you can without due care, you could end up with fewer fingers that you ought to have. For this reason, nukitsuke needs to be performed with the proper power behind the cut but also very carefully. This is where I have found the concept of 'Jo Ha Kyu' (slow-medium-fast pacing) to be invaluable to helping my technique.
The actual usage of this traditionally is much more complex but hopefully I can explain it briefly without offending too many practioners of formal martial arts.
Jo Ha Kyu makes up 3 different stages of, in this context, the nukitsuke cut.
- Jo, refers to the awareness of where you are physically and what you can do to make sure you are in the right position for your attack.
- Ha, you are starting your attack, beginning to draw the sword ready to cut with it.
- Kyu is about the sudden burst of speed and the cut itself.
Iaido uses this build up of speed extensively in forestalling, or controlling the actions of the opponent. I believe it is these slow deliberate starts and explosive finishes that make watching people proficient in Iaido so incredibly interesting to watch. When it comes simply to cutting however, the important part to understand here is that the tempo of the cut accelerates from very slow to fast and then abruptly stops.
Using this, you can start the most dangerous parts of the technique where the sword is still in the saya, before you make the final cut, all at a speed that you feel comfortable with. You can always speed up your drawing technique as you gain confidence and competence. Remember also, that the only part of the cut that matters where power is concerned, is the part that happens once the sword is entirely free of the saya. Again, this bodes well for your fingers.
Jo Ha Kyu as a formal martial arts technique is much more complex than this snippet and really demands its own research which I really reccommend, however if you are simply looking to improve your cutting from the saya, it is also a good set of ideas to improve your cut as well as keep you safe.