For many players, the clay court season is the most challenging time of the year as the clay takes the bite out of the serve and requires greater patience to win points.
But for the Spaniards and the South Americans, it is like Christmas!
Andy left Scotland to train outdoors on clay at the Sanchez-Casal Academy in Barcelona when he was 15, and that experience helped him improve his technique because you have to play many more shots.
Rafael Nadal: Aggressive, strong, quick and mentally tough
It also improved his court craft - with more time to hit the ball, shot selection has to be spot on as weak shots are often punished.
His time in Spain also improved his strength, speed, discipline, consistency and concentration.
On clay courts balls bounce relatively high and more slowly, making it difficult to hit an outright winner.
Players have to learn to create openings but must also develop a weapon to finish the point off.
Clay courts favour aggressive baseliners who are physically strong in both upper and lower body, quick off the mark and mentally tough through long points and long matches.
The slower bounce allows for bigger back swings which can generate extra power and the higher bounce encourages forehands with semi or full western grips to create heavy topspin.
British players have not been particularly successful on the clay circuit and this has much to do with spending their formative years training on fast indoor surfaces.
But it is a fantastic teacher. If you have access to clay, be sure to use it as much as possible.
On clay, topspin will kick up, forcing your opponent to hit difficult shoulder-height balls, hence the requirement for upper body strength.
In addition, sliced shots will really dig in; perfect for drawing your opponent up the court and for keeping the ball low, which makes it really tough for those players with western grips.
Drop shots and short angled slices work well on clay
Patience and control are key areas on clay too.
You need to hit lots of cross-court shots to try to take your opponents off the court and create an opening for a winner.
And you may have to hit many shots before you get the right chance to win the point.
So it is important you practise drills which involve at least six shots.
You must also practise changing the pace and depth of a shot, in order to disrupt your opponent's rhythm and try to take them off the baseline position.
Clay-courters tend to play in a semi circle about 5-10 feet behind the baseline.
This allows them time to get deep and wide shots back, though possibly leaving themselves vulnerable to the drop shot and the short angled shots.
So loopy deep balls, short angled slices, short angled topspins and drop shots are good weapons to have in the locker.
And remember, it is also a good idea to link shots to set your tactics.
So use a loopy deep ball to the backhand, followed by a cross-court drive volley.
Or try a loopy deep ball, followed by a drop shot to the opposite corner.
Other combinations that work are:
Short to mid-court angle, followed by a deep ball behind the opponent.
Cross-court forehand, followed by an inside-out forehand or cross-court backhand.
Drop shot, followed by a topspin lob or passing shot