Fluffy Vs Firm Sand

Fluffy sand offers less resistance than firm sand so the club can travel deeper through the sand much easier. This mandates that you need to control the depth better on fluffy sand and generally use a more shallow approach. It's more important to be smooth with your swing in fluffy sand than it is in firm sand.

Firm sand prevents the club from digging too deep into the sand. This means that you can be more aggressive with trying to hit down behind the ball. You need not worry about controlling depth as much, but must really be careful not to have too much tilt behind the ball. It's really easy for the club to skim off the sand and blade the ball if the sand is really firm.