I just pulled out some topo maps and figured out a way to hike a loop out from and back to the same trailhead, mostly avoiding the places I went in a previous hike there.
From the trailhead near Preacher Meadow (Swift Creek?), hike north, up Parker Creek, the to Lillypad Lake, to Boulder Lake, up and over to Conway, Lion, and Foster lakes, way down to Union Creek, back south to Mumford Meadow, up to Horseshoe and Ward lakes, then way down Kidd Creek, north to trail to Caribou, around to Snowslide and Caribou lakes, over Caribou Scramble and way way down to Stuart Fork, up to Emerald and Sapphire lakes, tried to get to Mirror Lake but too overgrown, back down Stuart Fork, past Morris Meadows, hopped ridge to Deer Creek, up Deer Creek and over Seven Up Pass, past Granite Lake and down Granite Creek, back to trailhead. This hike is all on existing trail.
If I hadn't been there before, I would've added the four lakes loop (Luella, Diamond, Summit, and Deer) and easy use-trail up to the top of Siligo Peak before going over Seven Up Pass.
My next hike there will be some variation of the "Trinity Alps High Route" (Google it), trying to be off trail as much as possible, and up on the higher granite.
Loop. Trailhead is red dot, hike is red, purple at bottom is short loop around Four Lakes.