Given the fact that the weather during most of the year is warm, the clothing should be comfortable and lightweight. In winter, however, include a coat since the nights are cool.
It is also important to have good shoes, since it is very likely that the trails are muddy so beware of slipping.
You must have spare clothing and shoes back at your hotel because getting wet is almost unavoidable.
Also carry a waterproof jacket.
And last but not least important, do not forget your sunglasses, sunscreen and bug spray.