When you play outdoor on a clay tennis court, one of the underrated factors is unpredictability. Clay courts are moody. When it’s warm and dry you can be versatile in your choice of tactics, but if the weather changes and court gets wet and the balls get heavy it is as if someone has flicked the slow motion switch. Even on a dry day it can be very difficult to play when a swirling wind gets up and blows the clay in your face. The most effective clay court players are those who are mentally tough and ready to adapt promptly and positively to all different challenges that get thrown at them.
You can expect the ball to bounce higher than on other surfaces when playing on clay. To take advantage of this many clay court specialists use relatively closed grips and an open stance base which allows them to whip up through the hitting zone to produce high-rolling topspin drives. A kicking second serve is also very useful.
You can expect the points to last longer than on other surfaces. You need to build up your physical and mental stamina. Even if you attack the net in an attempt to shorten the points, you should be ready to play two or three volleys in a row which is very demanding on the knees and thigh muscles.
You can expect movement to be difficult. As clay is not so firm underfoot as other courts, twisting and turning can present real problems. Make this work to your advantage by wrong footing your opponent. Try to master the art of sliding into your shots. You need to consistently practice these technical skills and build up your stamina.