Now I Lay Me Down To Sleep...Some pictures after the cut:
I've tried multi colored ITPs and they have come out very well!
As for adding another technique, I've been browsing the net on the matter and every technique seems to need quite a long time before the batter traces. All my stuff seems to trace fairly quickly.
Those look very nice, I'd buy a couple of bars on looks alone.
Lowering the temperature of your batter can extend 'play time', as can using an FO that behaves very well or is known to slow down trace.
@dibbles suggestion is great. Here is what I did for a three-layer soap...brown (Chocolate Ganche), white (Vanilla Bean) and Pink (Strawberry). Since I wanted somewhat straight layers I made up my oils and lye solution and then divided each by three. I then poured off that measurement of each into a second container, added my colorant and scent, blended to a light trace and poured. I let it set up...about an hour or so and then I poured off the second layer over a spatula (aka flooding), added colorant and scent, blended and poured. Let it set up and then mixed the last layer in the original container.
If I'm using a single scent, I'll just add it to the oils. If I'm not worried about perfect layers, I'll go ahead and mix the oils and lye solution to trace, then separate and use a spatula to flood.
When I make my Chocolate Espresso soap...brown layer, cocoa line, white topping with cocoa sprinkle, I do something different. I go ahead and combine the oils and lye solution then give it a really quick whiz (just short of emulsion) and separate out what I need for the topping and set aside. I then weigh out the FO for the bottom layer, added cocoa and brown oxide for an even discoloration, blend to medium trace, pour and add a cocoa line. Even at a medium trace, it can take quite a while for my soap to set up...which is why I why I do the quick whiz on the 'white topping'. I'm going to be adding a bit of TD to it and want to have control over it's consistency. While I wait for the brown layer to set, I usually make another soap or do some household chore. When it's time, I break out the whisk attachment for my stick blender...gotta be careful, it's not whip cream or egg whites so you have to go just short of 'stiff peaks'.