If you want the instrument to serve you longer, you don’t need too much for that.
It’s important to keep your ukulele in a case. If you don’t have it, then you should definitely buy it, especially considering that it’s not very expensive.
Why keep it in a case?
A few reasons:
The instrument will not get dusty. Also, as you probably won’t be changing the strings every day (or even every month), dust will settle on the strings rather quickly, unless it’s kept in a case.
Even if you don’t go with the Ukulele outside, the temperature and humidity is constantly changing, which has negative effects on the instrument.
The tuning will be kept longer and you won’t have to tune the Ukulele every time before playing.
When changing the strings, take a close look at the neck. Everyone sweats when playing, even if you can’t see it and the amount of sweat is not really big, it still solidifies and turns to dirt, especially close to the metal plates.
Take a toothbrush and lightly wipe all the frets. Also, music stores sell a special cleaning liquid for Ukuleles. Mind that you should never wipe it with a wet tissue, it’s bad for the instrument!