In many ways, the Tsuka is an important factor to the appearance of a sword. If the Tsuka is not made properly it will result in a less dignified appearance of the user, and also practically hinder his progress as a martial artist. If you look out for the points above, you should be able to tell a good Tsuka apart from a bad one to a certain extent. So please use this guide as a reference when you buy your next sword.
Having said this, no matter how good the Tsuka has been wrapped, if you use it incorrectly, any effort on choosing a sword with a properly wrapped Tsuka will be wasted.
Do not leave everything to your strength, you need to have a proper Tenouchi when you grip your sword. This say the Tsuka will also last longer, and when your Tsuka becomes damaged or loosens even though you have used it the correct way, please do not continue using it and consider to ask to have it re-wrapped.