From my own experience, lots of pushing hands at a high intensity - see what comes out. When you see a movement manifest that looks/feels like a part of your form, isolate that movement and drill it with a partner. Then in your solo training be mindful of the energy use that you found.
You can work at range after a while - see what happens when an opponent closes on you.
It's not as easy as being spoon fed applications, but it may make your taiji 'yours' sooner.
It's just one method - I'm only imparting the way I do it
Experience is something you don't get until just after you need it