The Toe to Heel tack is my favourite and I could ride and back forth doing them all day! But I did find this the hardest tack to learn - as @jumptheshark says the kite movement is pretty much the same for all the tacks. One small point I'd make on the kite movement that I've been playing with recently is that you can actually fly the kite up high before carving, then once it's close to the top of the window, it can then be easier to carve hard and pivot the foil around in a very tight arc. It's not the only way but some people find this easier (but you do need to more powered up) but for me, the other key part is the body position...
I tried Toe to Heel tacks for ages and they were so hit and miss. Often I found I just couldn't keep weight on my front foot as I came round, the foil stopped carving round and the foil/board would cant over towards me and I'd fall off downwind. Then I worked out what the difference was - to keep weight forwards all I need to do was really twist my shoulders and head to face the new direction, early in the carve upwind. That twisting motion gets your front shoulder forward into the turn and allows you to keep all your weight properly positioned over the board. Focus on pushing your front shoulder into the turn, this also helps with keeping tension on the kite lines as you can lean into them, olay the bar overhead and keep the kite powered up.
And one more thing, sheeting out - this is so important, you need to sheet right out, dump every bit of power as you start the hard carve, this lofts the kite over head allows you to duck under the lines.
I quickly made this video that hopefully shows how that front shoulder really helps to get you round in control (not the best quality but I don't have many shots of this trick film yet, just reference shots):
So to recap - 3 key tips:
- Drive the kite up to the top of the window
- As you start to carve upwind, sheet the bar out and twist your shoulders to face the new direction
- Focus on pushing your front shoulder into the turn, leaning into the bar