I prefer the slice drive as opposed to the floater, but they're both great imo.
While I don't really advocate the slice FH... I guess I want to comment on it anyways. And some of what I say here will... admittedly, sound or be a bit ignorant.
But my experience with slice shots, especially driven slice shots is that you just develop it out of experience like other things. However, the experience factor just seems big because to me, slice shots, especially driven, have always been so much about feel that it's too hard to communicate the little nuances that go on around contact.
If I were to describe my slice backhand, I guess two motions are going on at once. There's a volley like motion going on as my arm is steady but bent and my shoulder is doing a lot of the stroke work. And the second motion going on at the same time is a steady hip rotation that allows a nice upper body turn as I hit through the shot. Aside from that, I'm just thinking of being forward into the shot. ***And so that describes my approach to the technique of the slice backhand, but what's left out is what I'm feeling as I hit the shot.
As I hit any of the slice shots, at least lately, it's been too hard to describe. It's like how much slice or how much drive I put on the ball varies and it has more to do with what I'm feeling before/during/after contact with the ball. Height of the contact zone too. I guess just after time, I got some sort of "feel" for the shot, and so I vary it in subtle terms--and I can sort of already feel how the ball will cross the net. Whether I feather a forward moving, low pace, low bouncing (not sitting high) slice backhand. Or if I'm putting more drive in it and it's going at a much faster pace with virtually no kick, but a skid or a tiny skip. And if I'm being really defensive, then I can also exagerate the spin, lighten up the drive, and get something like a deep floater that sails to about half a foot before the baseline and sit up just a bit on bounce.
And all these adjustments just kind of came from a few moments when I suddenly "felt the ball" on slice shots, after a bunch of practice. I tend to over-mechanize my techniques, especially on anything that's driven.... But the slice shots have basically told me that some things are too hard to explain in exact detail or are at least better left to experiment and experience and feel---adjustments made as you're hitting--and tney are very subtle adjustments.
But we're talking the FH slice here... and what I can say is that the feel component is very much the same for me. I've been able to at least vary between floaters and half-drives. Nothing offensive like the big slice drive I do on the backhand side, but I've been able to hit adequately sliced drives with the forehand that are moderate pace with low skidding balls. Again, the feel is identical, the approach to technique is similar. I step into the ball, not too much arm movement as I drive the ball sorta high to low, my body tipped forward.
But to be redundant but honest... For me, anyways, it all just came from practice and a bit of experimentation. Simply because that feel factor just developed somewhere. I'll tell you that once I had that slice backhand in check, or at least got a feel for it, it applied directly to the forehand and I quickly developed a slice forehand as well as some drop shot ability with the forehand--at least cleaner drop shot ability with the forehand, anyways.
-Chanchai