When playing off of soft conditions like rough and soft sand, you want to open up the club face to effectively use the bounce on the sole of the club. More bounce prevents the head from digging too much.

The reverse is true in the opposite condition. If the ground is hard and has no give, then you do not want to open the face and maybe even close the face, if the bound angle on the club is too high. You will want to make sure to make ball first contact, because if you hit the hard ground first, the head may skip up and skull the ball.

Another method, which I haven't practiced much, is to stand more over the ball so that the heel of the club is off the ground and strike the ball on the toe of the wedge. This is more fore hard locations green side and not so much for bunkers.

For really wet sand, I will play it just like a normal bunker shot (open faced, ball forward, wrists hinged, etc) but I will use less bounce and/or try not to hit too far behind the ball.

That's all I got. Good luck.

Michael

In hard pan bunkers I play more of a pitch shot.  I use the 58-06 or the 64-07 for these but use a square clubface and still hit about an inch or two behind the ball but play more toward the center.   I CAN play an open face shot in hard sand; however, I have to play it back more and then the issue with trying to dig is coming over the top.  There is one shot where I have the choice of taking a full swing with a 64 or a half swing with the 58. 

With wet sand, the 58-06 works nicely with an open face shot.

I'm fortunate to have 3 types of bunkers on the military courses in SD.  The sand at Miramar is hard as a rock and the bunker is pretty large so I hit a 58 in the back and a 64 in the middle.   Admiral Baker has a soft bunker by the driving range and I do open face shots with all my wedges (I go to the back with a PW or 50-08 , in the middle with the 54 and do short shots with the 58 or 64).  The clubhouse bunker is wet so the 58 is ideal.

Michael Breed has some great bunker tips on varying conditions. 

I used to use a 60-10 up until recently when the winter rains in San Diego made the bunkers at Adm Baker like concrete - hence the switch to the 58-06. 

thanks for the replies

Another thing to remember is that the ball may come off the face hotter with a square clubface (allow for roll)

I find that wet or firm sand is the easiest if you are used to it,  playing in Canada a lot of courses have very firm sand in early part of the year after the winter,   I have found that green side opening the face and hitting about an inch behind the ball on a shollower plane produces a very nice high lob with lots of spin.  

I have a very low bounce vokey and the shot is very consistent , but practice is essential.   Once the shallower plane is comfortable and you have the proper bounce with the wedge the shot actually is much simpler and has a wide margin for error compared to soft sand .    

If you don't have a lower bounce wedge ,  using a square pitching or sand wedge and driving in behind (again about am inch ) will provide good results .    remember for these shots not as much swing speed is need as you take about only 25% of the sand vs a conventional explosion shot.

Give it a try.   

Mike

+1.2  golfer Canada.  

Don't forget about the classic technique of using a putter and just running the ball up the wall like some kind of Motor Cross jump. I've done it a hand full of times by accidentally skulling the bejesus out of the ball. Terrible shot, but great results.

Luck is one of my skills.